Uptime Report Research · PIR casebook

Azure Outage History: 127 of 219 Microsoft Post Incident Reviews Began With Microsoft’s Own Change

Azure outage history, case by case: we recovered 219 post incident reviews (PIRs) that Microsoft published on its Azure status history page from November 2016 to September 2026, and 127 of them (58%) describe an Azure outage that began with Microsoft’s own configuration change, code rollout or maintenance work. The median impact window was 5 h 45 min. Power and cooling caused 25.

Case files

219Azure PIRs and RCAs coded, 2016 to 2026 (78 still on Microsoft’s page)

Own change

58%began with a Microsoft config change, rollout or maintenance (127 of 219)

Median window

5 h 45 minfrom first impact to mitigation (215 reviews with both times)

Power and cooling

14 of 66reviews since June 2022, against 6 of 88 before Nov 2019

2026 so far

10reviews Jan to Sept 2026; 3 were power events

Microsoft writes a PIR after each broad Azure incident and posts it on azure.status.microsoft. The page keeps each review for five years, so it currently shows 81 entries starting in November 2021 (it showed 84 on October 13, 2026, before 3 older ones aged out). We pulled every entry through the page’s own history endpoint, then recovered older reviews from 101 Internet Archive captures of the page under its three past addresses. We read each review and coded what started the incident, then parsed the impact window and regions from Microsoft’s own summary. This is the same method we used for the AWS outage history and the Cloudflare outage post-mortems.

The biggest Azure outages, in Microsoft’s words

Eight case files stand out for reach, length, or what they reveal. Each quote is a sentence from the PIR itself.

YKYN-BWZOct 29, 2025

Azure Front Door, Connectivity issues across multiple regions

8 h 24 min impact window · multiple regions or global

“A specific sequence of customer configuration changes, performed across two different control plane build versions, resulted in incompatible customer configuration metadata being generated.”

Latent bug, no change named Read the PIR

QNBQ-5W8Oct 09, 2025

Azure Front Door, Access issues in multiple regions

8 h 10 min impact window · multiple regions or global

“By bypassing the protection system, the erroneous metadata was inadvertently able to propagate to later stages, and triggered the bug in the data plane that crashed the data plane service.”

Configuration or operational change Began with a Microsoft change Read the PIR

1K80-N_8Jul 18, 2024

Storage, Impact to multiple services in Central US

1 d 20 min impact window · Central US

“The workflow which generates the list did not detect the ‘missing’ source files, and published an allow list with incomplete VM Host address range information to all Storage scale units in the region.”

Configuration or operational change Began with a Microsoft change Read the PIR

GHRP-84GMay 29, 2026

Multiple services, Power/cooling issues in West US 2

22 h 6 min impact window · West US 2

“A severe thunderstorm produced lightning strikes, resulting in utility power disturbances across multiple datacenter facilities serving the West US 2 region.”

Power or cooling Read the PIR

_SVS-5_GFeb 07, 2026

Power event impacting multiple services, West US

20 h 26 min impact window · West US

“During this incident, although utility power was still active, an electrical failure in an onsite transformer resulted in the loss of utility power to the datacenter.”

Power or cooling Read the PIR

FNJ8-VQZFeb 02, 2026

Virtual Machines, Managed identities for Azure resources, and dependent services, Service management issues in multiple regions

6 h 27 min impact window · multiple regions or global

“Due to a data synchronization problem in the targeting logic, the policy was incorrectly applied to a subset of storage accounts that are intentionally configured to allow anonymous read access for platform functionality.”

Configuration or operational change Began with a Microsoft change Read the PIR

VN11-JD8Feb 07, 2023

Multi-service outage, Asia-Pacific Area

1 d 8 h 11 min impact window · Southeast Asia, East Asia

“Power management systems managed the voltage dip as designed, however a subset of chiller units that provide cooling to the datacenter tripped and shut down.”

Power or cooling Read the PIR

LN01-P8ZMar 15, 2021

Authentication errors across multiple Microsoft services

14 h 37 min impact window · multiple regions or global

“This exposed a bug where the automation incorrectly ignored that “retain” state, leading it to remove that particular key.”

Latent bug, no change named Read the PIR

Impact window: first and second times in the PIR’s opening summary, converted to UTC. Card colour shows the root-cause category.

The two Azure Front Door reviews of October 2025 belong together. On October 9, Microsoft temporarily bypassed a protection system to clean up bad tenant metadata, and the metadata crashed the data plane in about 26% of Front Door resources in Europe and Africa; a second review the same day covers the management portals that went down with it. Twenty days later a valid customer configuration change produced metadata that hit a latent data plane bug, and the October 29 incident lasted 8 h 24 min. Front Door appears in 13 reviews in total.

Azure outages in 2026 so far

Microsoft has published 9 reviews for incidents between January and September 2026, and an Internet Archive capture preserves one more that is no longer on the page. 3 of the 10 were power or cooling events in the western US, including the two longest of the year.

Date	Tracking ID	Incident	What started it	Window
Jan 10	XM22-5_G	Power event impacting multiple services in AZ01, West US 2 (archive only)	Power or cooling	7 h 33 min
Feb 02	FNJ8-VQZ	Virtual Machines, Managed identities for Azure resources, and dependent services, Service management issues in multiple regions	Configuration or operational change	6 h 27 min
Feb 07	_SVS-5_G	Power event impacting multiple services, West US	Power or cooling	20 h 26 min
Mar 09	8GCS-858	Azure OpenAI, GPT-5.2 availability degradation in 7 regions	Configuration or operational change	20 h 12 min
Apr 24	5GP8-W0G	Multiple services, Control plane issues in East US	Latent bug, no change named	11 h 52 min
May 29	LYXT-C1Z	Azure OpenAI Service, Latency and intermittent failures in multiple regions	Code or update rollout	7 h 26 min
May 29	GHRP-84G	Multiple services, Power/cooling issues in West US 2	Power or cooling	22 h 6 min
Jul 23	ZJV6-SGG	Network connectivity, Issues accessing resources in West US	Configuration or operational change	4 h 57 min
Sep 29	7QL5-Z50	Azure OpenAI Service, Foundry Agent Service, Foundry Models, and Azure AI services, Intermittent request failures and latency in Sweden Central	Code or update rollout	5 h 55 min
Sep 30	7Q30-010	Network Connectivity, Gateway service degradation in multiple regions	Code or update rollout	5 h 45 min

The January 10 entry (XM22-5_G) was a preliminary review for a West US 2 power event that a later capture no longer shows; Microsoft removes some entries once the final review goes privately to affected customers.

What causes Azure outages?

Configuration and operational changes lead every era. Across all 219 reviews, 78 began with a configuration or operational change (including maintenance, migrations and capacity work) and 38 with a code, OS or certificate rollout. Only 21 describe a latent bug that surfaced without a change Microsoft names. Physical causes are smaller but growing: 25 power or cooling events and 22 hardware, fiber or network device faults.

Configuration or operational change (78)Code or update rollout (38)Latent bug, no change named (21)Load or capacity (23)Power or cooling (25)Hardware, fiber or network device (22)Third party or attack (11)Not determined (1)

Eras follow Microsoft’s own publishing rules for the history page. The first era is a sample: the page then showed only recent items, and captures exist for some months only.

The power share rose from 7% of reviews before November 2019 to 21% since June 2022. The two periods are not like for like: since June 1, 2022 the page only carries PIRs for broad issues, so smaller incidents of every kind dropped out. Changes still started most incidents: 38 of 66 since June 2022. Of the 14 power or cooling reviews in that period, 11 describe impact confined to a single Availability Zone.

Era	What the page covered	Reviews	Began with a Microsoft change	Power or cooling	Hardware or fiber	Third party or attack	Median window
2016 to Nov 19, 2019	archive sample	88	49 (56%)	6 (7%)	10	5	5 h 13 min
Nov 20, 2019 to May 2022	all publicly communicated issues	65	40 (62%)	5 (8%)	6	3	4 h 41 min
June 2022 to Sept 2026	broad issues only	66	38 (58%)	14 (21%)	6	3	8 h 36 min

Which Azure regions have the most outages?

West Europe is named in 34 reviews, more than any other region, followed by East US and East US 2. Reviews naming at least one US region total 57. But the most common answer is no single region: 92 reviews (42%) describe global, multi-region or service-wide faults, led by identity (21), networking (17), Resource Manager and the portal (14) and Front Door (10). For those, picking a different region would not have helped.

Darker: more reviews that yearNo single region named

Regions named in four or more reviews, from the title and opening summary of each PIR. A review naming two regions counts in both rows. *2026 runs to September.

How long Azure outages last

The median impact window across 215 reviews is 5 h 45 min, and half of all windows fall between 2 h 44 min and 10 h 7 min. Power and cooling events run longest, at a median of 8 h 32 min. Hardware, fiber and network device faults, and third-party problems, are the shortest, at 3 h 15 min and 3 h 10 min.

Median per category

Log scale. One dot per review with a start and end time in its summary. Some long windows cover slow, partial impact (for example metrics delays) rather than a hard outage.

Every Azure post incident review in one table

All 219 reviews, newest first. The key sentence is taken verbatim from each review’s root-cause section, chosen by our script as the sentence that most directly states the cause.

Date	Tracking ID	Incident	What started it	Own change?	Window	Regions named	Key sentence (verbatim)
2026-09-30	7Q30-010	Network Connectivity, Gateway service degradation in multiple regions	Code or update rollout	Yes	5 h 45 min	None named	Before this incident, a temporary deployment restriction had paused operating system updates for a group of networking gateways.
2026-09-29	7QL5-Z50	Azure OpenAI Service, Foundry Agent Service, Foundry Models, and Azure AI services, Intermittent request failures and latency in Sweden Central	Code or update rollout	Yes	5 h 55 min	Sweden Central	As part of this deployment, the internal service’s caches were cleared and – because the deployment coincided with peak traffic hours in the region – this produced a large number of cache misses, where requests were made for information no longer stored in the cache.
2026-07-23	ZJV6-SGG	Network connectivity, Issues accessing resources in West US	Configuration or operational change	Yes	4 h 57 min	West US	A defect in our blast radius analysis system incorrectly expanded the scope of the repair event to include all optical devices egressing a specific datacenter.
2026-05-29	LYXT-C1Z	Azure OpenAI Service, Latency and intermittent failures in multiple regions	Code or update rollout	Yes	7 h 26 min	Australia East	The triggering condition was a change in an upstream API layer used by a Microsoft first-party workload, Microsoft 365, which relies on Azure OpenAI for some request processing scenarios, including Copilot-related experiences.
2026-05-29	GHRP-84G	Multiple services, Power/cooling issues in West US 2	Power or cooling	No	22 h 6 min	West US 2	A severe thunderstorm produced lightning strikes, resulting in utility power disturbances across multiple datacenter facilities serving the West US 2 region.
2026-04-24	5GP8-W0G	Multiple services, Control plane issues in East US	Latent bug, no change named	No	11 h 52 min	East US	During normal platform operations, one partition of the PubSub control plane service in a single Availability Zone (AZ-01) experienced lock contention errors for several minutes, resulting in operations on that partition to timeout and fail.
2026-03-09	8GCS-858	Azure OpenAI, GPT-5.2 availability degradation in 7 regions	Configuration or operational change	Yes	20 h 12 min	Australia East, Central US, East US 2, Korea Central, Norway East, Sweden Central, UK South	A recent update to the Azure OpenAI GPT 5.2 model introduced a configuration change that was not compatible with the version of the model engine code running in production.
2026-02-07	_SVS-5_G	Power event impacting multiple services, West US	Power or cooling	No	20 h 26 min	West US	During this incident, although utility power was still active, an electrical failure in an onsite transformer resulted in the loss of utility power to the datacenter.
2026-02-02	FNJ8-VQZ	Virtual Machines, Managed identities for Azure resources, and dependent services, Service management issues in multiple regions	Configuration or operational change	Yes	6 h 27 min	None named	Due to a data synchronization problem in the targeting logic, the policy was incorrectly applied to a subset of storage accounts that are intentionally configured to allow anonymous read access for platform functionality.
2026-01-10	XM22-5_G	Power event impacting multiple services in AZ01, West US 2	Power or cooling	No	7 h 33 min	West US 2	This sudden loss of power caused the affected hardware to shut down, resulting in interruptions for services dependent on those resources.
2025-12-22	FV31-PQG	Entra Privileged Identity Management, Customers experiencing API failures	Configuration or operational change	Yes	10 h 25 min	None named	As part of ongoing work to improve how the PIM service stores and manages data, configuration changes which manage the backend databases were deployed incrementally using safe deployment practices.
2025-12-08	ML7_-DWG	Azure Resource Manager, Service management failures affecting Azure Government	Configuration or operational change	Yes	3 h 9 min	None named	On 08 December 2025, an inadvertent automated key rotation resulted in ARM failures to fetch authorization policies that are needed to evaluate access.
2025-12-08	JSNV-FBZ	Azure Resource Manager, Service management failures affecting Azure in China	Configuration or operational change	Yes	9 h 10 min	None named	On 08 December 2025, an inadvertent automated key rotation resulted in ARM failures to fetch authorization policies that are needed to evaluate access.
2025-11-05	2LGD-9VG	Thermal event impacting multiple services in AZ01, West Europe	Power or cooling	No	9 h 32 min	West Europe	The incident was triggered by a voltage sag in the utility grid, which caused cooling units to shut down and temperatures to rise above normal thresholds in a datacenter located in Physical Availability Zone 01 in the West Europe region.
2025-10-29	YKYN-BWZ	Azure Front Door, Connectivity issues across multiple regions	Latent bug, no change named	No	8 h 24 min	None named	A specific sequence of customer configuration changes, performed across two different control plane build versions, resulted in incompatible customer configuration metadata being generated.
2025-10-09	QKNQ-PB8	Azure Portal and other management portals, Access issues in multiple regions	Configuration or operational change	Yes	4 h 16 min	None named	Automation scripts were used to update the traffic load balancing configuration to split traffic across multiple routes.
2025-10-09	QNBQ-5W8	Azure Front Door, Access issues in multiple regions	Configuration or operational change	Yes	8 h 10 min	None named	By bypassing the protection system, the erroneous metadata was inadvertently able to propagate to later stages, and triggered the bug in the data plane that crashed the data plane service.
2025-09-26	BT6W-FX0	Network Connectivity, Multiple services impacted in Switzerland North	Configuration or operational change	Yes	22 h 5 min	Switzerland North	This type of planned change is intended to be impactless but, due to the malformed certificate, authorization of connectivity for load balancer between nodes and resources could not complete.
2025-09-10	VKY3-PF8	Service management operations failures in East US 2	Code or update rollout	Yes	9 h 47 min	East US 2	However, a performance issue affecting a subset of Allocator machines triggered the new throttling logic which, because of the high throughput demand in the East US 2 region, caused VM provisioning requests to retry more aggressively than the control plane could handle.
2025-03-18	Z_SZ-NV8	Network Connectivity, Availability issues in East US	Hardware, fiber or network device	No	3 h 15 min	East US	Due to some capacity being out of service from the fiber cut, this failed state was not immediately flagged in our systems as the down capacity was not carrying production traffic.
2025-03-03	ZT0X-9B8	Network Connectivity, Toronto edge site issues	Hardware, fiber or network device	No	2 h 15 min	None named	While we were performing an initial investigation into the cause of device failure, at 16:22 UTC the redundant device also experienced a hardware failure, due to a similar memory issue on the line cards – the line cards restarted, and did not initialize properly after startup, to forward traffic.
2025-02-25	TMS9-J_8	Microsoft Entra ID, DNS authentication failures for single sign-on and Entra Connect Sync	Configuration or operational change	Yes	8 h 33 min	None named	As part of an ongoing maintenance effort, a change was made which inadvertently removed an intermediate DNS record and associated traffic manager used in the mentioned scenarios.
2025-01-08	PLP3-1W8	Networking issues impacting Azure Services in East US 2	Configuration or operational change	Yes	2 d 2 h 13 min	East US 2	In this case, recycling was executed across the replicas in ‘parallel’, causing the partition to lose quorum.
2024-12-26	CNF4-N_0	Services impacted after zonal power issue, South Central US	Power or cooling	No	1 d 50 min	South Central US	This incident was initially triggered by a utility power loss, itself caused by a localized ground fault, in which a high voltage underground line failed.
2024-11-13	PSM0-BQ8	Azure Storage, Unreachable Blob and Data Lake storage accounts in multiple regions	Configuration or operational change	Yes	11 h 40 min	None named	The incident was caused by an unintentional deletion of Traffic Manager profiles for the impacted storage accounts.
2024-09-27	HSKF-FB0	Azure Resource Manager, Issues in Azure US Government regions	Configuration or operational change	Yes	1 h 38 min	US Gov Arizona, US Gov Texas, US Gov Virginia	When this account was misconfigured, the change immediately applied to all replicas impacting ARM in all regions.
2024-09-16	1LG8-1X0	Azure Virtual Desktop, Unable to create new connections, impacting US regions	Latent bug, no change named	No	1 h 50 min	East US 2, Central US, East US, North Central US, South Central US, West Central US, West US, West US 2, West US 3	We determined that this incident was caused by a degradation in the redo process on one of the secondary copies servicing the US geography, which caused failures to access service resources.
2024-09-05	HVZN-VB0	Azure Resource Manager, Control plane issues in China North 3	Configuration or operational change	Yes	13 h 30 min	China North 3	The certificate rotation in the Azure China regions exposed a latent bug in the update process which caused the processes to begin crashing.
2024-08-05	0N_5-PQ0	Azure Front Door, Intermittent issues with Microsoft services using AFD	Configuration or operational change	Yes	1 h 27 min	None named	This initial impact on availability triggered a latent bug in the internal service’s client application, which caused an aggressive request storm.
2024-07-30	KTY1-HW8	Azure Front Door, Connectivity issues in multiple regions	Third party or attack	No	2 h 13 min	None named	This happened because of Network control plane failures to that specific site, due to a local power outage.
2024-07-18	1K80-N_8	Storage, Impact to multiple services in Central US	Configuration or operational change	Yes	1 d 20 min	Central US	The workflow which generates the list did not detect the ‘missing’ source files, and published an allow list with incomplete VM Host address range information to all Storage scale units in the region.
2024-07-13	4L44-3F0	Azure OpenAI Service, Errors in multiple regions	Configuration or operational change	Yes	23 h 35 min	Australia East, Brazil South, Canada Central, Canada East, East US 2, France Central, Korea Central, North Central US, Norway East, Poland Central, South Africa North, South India, Sweden Central, UK South	Because the configuration change was delivered as a content update at a global scope, there existed no safe deployment process to gate the effect of the change in region-specific order, resulting in a multi-region incident.
2024-07-12	FTVR-L9Z	Managed Identities for Azure resources, Failures in Australia East	Configuration or operational change	Yes	5 h 33 min	Australia East	The process for rolling out this change was to deploy a service change to support automatic keys, and then roll over our keys into the new system in each region one-by-one, following our safe deployment process.
2024-04-22	V_BH-7DZ	DNS resolution issues impacted Azure in China	Configuration or operational change	Yes	2 h 15 min	None named	As DNS caches across the Internet gradually timed out, DNS resolvers made requests to refresh the information for the two domains and received responses containing the inactive nameservers, resulting in failures to resolve FQDNs in those domains.
2024-04-19	QS3K-BPZ	Azure Database for MySQL/MariaDB in West US, Azure Databricks in 3 regions	Configuration or operational change	Yes	3 h 4 min	West US, West US 2, South Central US	As part of ongoing service maintenance, compute hardware hosting the gateway service is periodically refreshed to ensure we provide the most secure and performant experience.
2024-03-14	VT60-RPZ	Network connectivity – Multiple services impacted in South Africa North and South Africa West	Hardware, fiber or network device	No	1 d 27 min	South Africa North, South Africa West	In this case, our South Africa Regions has four physically diverse subsea cable systems serving the country and the designed failure mode is that three out of four can fail with no impact to our customers.
2024-01-21	NKRF-1TG	Azure Resource Manager – Services impacted by ARM failures	Configuration or operational change	Yes	7 h 28 min	Central US, East US, South Central US, West Central US, West Europe	On 21 January 2024, an internal maintenance process made a configuration change to an internal tenant which was enrolled in this preview.
2023-10-20	MM12-HSG	Services impacted after power issue – West Europe	Power or cooling	No	not stated	West Europe	A subset of those generators supporting that section failed to take over as expected during the switch over from utility power, resulting in the impact.
2023-09-16	2LZ0-3DG	Services impacted by power, BIOS, and Virtual Machine issues, East US	Power or cooling	No	11 h 36 min	East US	This logic prevented the STS from transferring back to the redundant power, after the primary UPS failed completely, which ultimately caused a power loss to a subset of the scale units within the datacenter, at 07:24 UTC, for 1.9 seconds.
2023-08-30	VVTQ-J98	Services impacted after power/cooling issue – Australia East	Power or cooling	No	not stated	Australia East	Starting at approximately 08:41 UTC on 30 August 2023, a utility voltage sag was caused by a lightning strike on electrical infrastructure approximately 18 miles from the impacted Availability Zone of the Australia East region.
2023-07-06	XMGF-5Z0	Azure Monitor – Logs data access issues	Code or update rollout	Yes	9 h 45 min	None named	A code deployment for the Azure Container Apps service was started on 3 July 2023 via the normal Safe Deployment Practices (SDP), first rolling out to Azure canary and staging regions.
2023-07-05	FVHB-188	Networking fiber cut – West Europe	Hardware, fiber or network device	No	8 h 38 min	West Europe	Due to a fiber cut caused by severe weather conditions in the Netherlands, 25% of network links between two campuses of West Europe datacenters became unavailable.
2023-06-16	VLB8-1Z0	Networking connectivity issues – West Europe	Configuration or operational change	Yes	4 h 51 min	West Europe	This network topology description incorrectly listed these links as being ‘Production’.
2023-06-09	QNPD-NC8	Azure Portal – Errors accessing the Azure portal	Load or capacity	No	1 h 50 min	None named	However, this attack resulted in the issues mentioned above, and we have hardened our protections from the lessons we’ve learned from it.
2023-03-23	RNQ2-NC8	Azure Resource Manager, West Europe	Code or update rollout	Yes	5 h 10 min	West Europe	This was caused by high-volume, short-held lock contention on the request serving path, which triggered a significant increase in spin-waits against these locks, driving up CPU load and preventing threads from picking up asynchronous background work.
2023-03-06	R_36-P80	Azure Storage – West Europe	Configuration or operational change	Yes	14 h 5 min	West Europe	While this configuration change followed the usual Safe Deployment Practices (for more details, refer to: https://learn.microsoft.com/en-us/devops/operate/safe-deployment-practices ), this issue was found mid-way through the deployment.
2023-02-07	VN11-JD8	Multi-service outage, Asia-Pacific Area	Power or cooling	No	1 d 8 h 11 min	Southeast Asia, East Asia	Power management systems managed the voltage dip as designed, however a subset of chiller units that provide cooling to the datacenter tripped and shut down.
2023-01-31	BS81-390	Service management issues – East US 2	Load or capacity	No	19 h 3 min	East US 2	Each of these AZs are further internally sliced into partitions, to ensure that a failure in one partition does not affect the processing in other partitions.
2023-01-25	VSG1-B90	Azure Networking, Global WAN issues	Configuration or operational change	Yes	5 h 35 min	None named	This unqualified change led to a chain of events which culminated in the widespread impact of this incident.
2023-01-23	7NBR-T98	Intermittent networking issues – South Central US	Hardware, fiber or network device	No	3 h 59 min	South Central US	During this incident, a single router in the RNG experienced a hardware fault, causing a fraction of network packets to be dropped.
2023-01-23	2TFR-NC0	Azure Synapse Analytics – West Europe	Power or cooling	Yes	15 h 40 min	West Europe	We determined that an issue occurred during a planned power maintenance, causing an incident for a subset of storage and networking infrastructure in one datacenter of one Availability Zone in West Europe.
2023-01-18	6S_Q-JT8	Single zone power event, West Europe	Power or cooling	Yes	3 h 26 min	West Europe	While all server racks have redundant dual feeds, one feed was powered down for maintenance, and a failure in the redundant feed caused a shutdown of the affected racks.
2022-11-02	YTGZ-1Z8	Enrolling new certificates / Provisioning new resources – Azure Public / Government / China	Latent bug, no change named	No	1 d 5 h 13 min	None named	Due to a latent performance bug in the RA, inadvertently introduced in the past month as part of a feature enhancement, the rate of new incoming requests was greater than the rate at which requests could be processed from the queue.
2022-10-26	JKWW-JP8	Azure Cosmos DB – East US	Configuration or operational change	Yes	5 h 35 min	East US	A change to the front-end gateway of Azure Cosmos DB, to include additional diagnostic information, was introduced on the affected cluster earlier this month.
2022-09-07	3TPC-DT8	Azure Cosmos DB – North Europe	Configuration or operational change	Yes	7 h 31 min	North Europe	Our frontend load balancing procedure had a regression that did not factor in the effect of a reduction in available cluster capacity, due to ongoing maintenance.
2022-09-07	YV8C-DT0	Azure Front Door – Connectivity Issues	Third party or attack	No	3 h 45 min	None named	The first two spikes were successfully absorbed due the platform protection mechanisms, however the ones that were initiated during the third spike did not fully mitigate the unexpected increase due to the nature of the traffic pattern (different from the first two spikes).
2022-08-30	2TWN-VT0	Canonical Ubuntu issue impacted VMs and AKS	Third party or attack	No	1 d 10 h	None named	The manifestation of this bug was triggered due to the combination of this and a previous update.
2022-08-27	MMXN-RZ0	Datacenter power event – West US 2	Power or cooling	No	23 h 13 min	West US 2	In the first datacenter, impact was caused when a small number of server rack level Uninterruptible Power Supply (RUPS) systems failed to stay online during the transition to generator, creating a momentary loss of power to the servers.
2022-08-18	YLBJ-790	Azure Key Vault – Provisioning Failures	Load or capacity	Yes	9 h 52 min	None named	During the incident, a backend service that Azure Key Vault relies on, became unhealthy due to an unexpected spike in traffic during scheduled hardware maintenance, which caused a build-up of requests in the queue, resulting in high latencies to fulfil new certificate creation requests.
2022-08-12	YTYN-5T8	Azure Communication Services – Multiple Regions	Configuration or operational change	Yes	9 h 17 min	None named	This change in database capacity inadvertently exposed a latent code bug for the resource provider, which resulted in a functional difference in the number of database results being returned against what could be processed by the resource provider.
2022-07-29	7SHM-P88	Network Connectivity Issues	Load or capacity	No	5 h 20 min	Brazil South, Canada Central, East Asia, East US, East US 2, France Central, Japan East, Korea Central, North Central US, South Africa North, South Central US, Southeast Asia, West Europe, West US	While the event was detected immediately and automated remediation was triggered, the substantial increased bursts of traffic occurring throughout the event affected the ability of automated mitigations to continue providing the necessary relief to the network.
2022-07-21	3TBL-PD8	SQL Database – West Europe	Configuration or operational change	Yes	9 h 43 min	West Europe	An operator error led to an incorrect action being performed in close sequence on all four persisted metadata caches.
2022-06-29	YKDK-TT8	Wide Area Network – Multiple Regions	Hardware, fiber or network device	No	17 h 34 min	None named	On this single faulty router, only four of its 140 physical ports had a physical failure, which was causing a section of the router to malfunction intermittently without producing an actionable error message.
2022-06-28	YVTL-RS0	Azure Software Load Balancer – Multiple Regions	Code or update rollout	Yes	2 d 22 h 34 min	None named	Upon investigating this issue, we identified a change in our latest code deployment which caused some MUX instances to store the backend DIPs in a different order.
2022-06-14	3V1K-5D8	Azure Front Door – Connectivity Issues	Power or cooling	No	4 h 29 min	None named	The electrical transients were introduced by anomalous component behavior within Uninterruptible Power Supply (UPS) modules, and cascaded throughout the datacenter electrical distribution system including electrical power supply to the mechanical cooling plant.
2022-06-07	NMB2-ND0	Datacenter cooling event – East US 2	Power or cooling	No	11 h 49 min	East US 2	The electrical transients were introduced by anomalous component behavior within Uninterruptible Power Supply (UPS) modules, and cascaded throughout the datacenter electrical distribution system including electrical power supply to the mechanical cooling plant.
2022-05-31	YL23-V90	Azure Active Directory Sign In logs	Configuration or operational change	Yes	12 h 19 min	None named	As part of continuous service improvements, a recent change to the underlying infrastructure that was intended to optimize performance, inadvertently caused the observed impact.
2022-04-08	Y__5-9C0	Service Management Operation Errors Across Azure Services in East US 2	Load or capacity	No	1 d 2 h 15 min	East US 2	The underlying issue was a retry storm triggered by the zonal failure of a related Allocator service.
2022-03-16	TTCR-NTZ	Azure AD B2C, Authentication Failures and Error Notifications	Load or capacity	Yes	1 h 9 min	None named	The service experienced a significant increase in workload in the affected region during a planned maintenance operation.
2022-03-01	ZNRZ-HDG	Azure Resource Manager – Service Management Operation Failures	Configuration or operational change	Yes	1 d 15 h 19 min	None named	A configuration change was applied to these backend components, which resulted in some instances of the ARM service becoming unreachable, causing errors for a subset of operation requests.
2022-02-16	9TDP-N8G	SQL Database and App Service – West Europe	Hardware, fiber or network device	No	8 h	West Europe	Due to a memory hardware failure in a network router, a control plane/data plane synchronization process in that router failed during a regular automated maintenance operation.
2022-02-12	SL1P-TSZ	Azure SQL DB and Cosmos DB Unavailable	Latent bug, no change named	No	2 d 23 h 58 min	None named	A race condition in the underlying Remote Procedure Call (RPC) mechanism caused the network control plane channel in some cases to not pick up the rotated certificate, leading to connectivity failures once the certificate expired.
2022-02-02	SMWW-BDZ	Azure AD – Service Management Failures	Configuration or operational change	Yes	2 h 16 min	None named	As part of planned maintenance, a change to a dependency was rolled out which affected the availability of the Azure AD REST API service.
2022-01-13	8V39-P9Z	Azure Resource Manager – Issues with management and resource operations	Code or update rollout	Yes	1 d 11 h	West US, West US 2, South Central US, North Europe, West Europe, East Asia, Southeast Asia	A code modification which started rolling out on 6 Jan 2022 exposed a latent defect in the infrastructure used to process long running operations (informally, “jobs”).
2022-01-04	9VT8-HPG	Azure Cosmos DB – East US	Latent bug, no change named	No	19 h 11 min	East US	Service Fabric uses the ring topology, and each node establishes a lease relationship with nodes in its proximity (i.e. neighborhood) to detect failure.
2021-12-16	S_3M-FZZ	Azure Active Directory – Experiencing sign in issues when attempting to access Azure, Dynamics 365, and/or Microsoft 365 Services	Code or update rollout	Yes	1 h 25 min	None named	In this case, due to a gap in the backend service’s health monitoring, the update rollout was not stopped until all redundant endpoints were impacted.
2021-12-13	8T9M-T9G	Azure Data Factory V2 – West Europe	Latent bug, no change named	No	6 h	West Europe	Retry logic from ADF, coupled with this unhealthy service, resulted in a rare combination of transient conditions and lead to additional errors.
2021-12-09	SNCJ-9ZG	Errors connecting to SCM App Service and/or Azure Functions deployments	Configuration or operational change	Yes	3 h 23 min	None named	However, due to a misconfiguration, this change incorrectly affected the name resolution for App Service SCM endpoint, which resulted in a subset of our customers not being able to connect to the SCM endpoints of the service.
2021-11-16	SVT2-VCZ	Azure Active Directory – Issues when attempting to authenticate	Latent bug, no change named	No	2 h 40 min	None named	The engineering team has determined that an underlying code defect triggered some service nodes to experience a shortage of outbound ports to complete network tasks.
2021-11-09	DK83-BDZ	Intermittent Failures When Accessing or Using Access Panel	Code or update rollout	Yes	5 h 25 min	West Central US, Central US	After we failed to detect this bug through testing, it was discovered during telemetry validation in the first deployment stage in West Central US, at which point we failed over traffic from West Central US to Central US at 07:00 UTC to prevent customers from experiencing this discovered bug.
2021-10-13	0NC_-L9G	Virtual Machines	Configuration or operational change	Yes	6 h 15 min	None named	Using this information, the VM Agent will update itself to the latest version in the VM.
2021-08-11	0MQY-NPG	Connection errors for resources leveraging Azure Front Door and Azure CDN	Code or update rollout	Yes	3 h	Japan East, Japan West, Korea South, Korea Central, West US	A subset of edge locations in Korea, Japan, and West US were running with stale TLS resumption keys, and the rolled-out update triggered the mechanism to prevent the reuse of stale keys.
2021-07-28	LNZM-TZG	Azure Network Infrastructure service availability issues – Brazil Southeast	Configuration or operational change	Yes	1 h 32 min	Brazil Southeast	We determined that a degradation in connectivity was caused by packet loss when the metadata on one of our regional-level routers was updated incorrectly.
2021-07-23	5TGJ-1SZ	Service availability issue – Brazil South	Configuration or operational change	Yes	2 h 28 min	Brazil South	During this maintenance activity, a technician was executing a change that impacted the incorrect set of cables.
2021-07-21	4LRL-V8G	Azure Cognitive Services	Code or update rollout	Yes	6 h 55 min	None named	Our investigation revealed that this issue was triggered by a pending (deployed, but awaiting reboot) OS security update which had introduced a networking change on the updated clusters.
2021-07-21	4VWK-LPZ	Azure Cognitive Services – Azure Government	Code or update rollout	Yes	6 h 55 min	None named	Our investigation revealed that this issue was triggered by a pending (deployed, but awaiting reboot) OS security update which had introduced a networking change on the updated clusters.
2021-07-12	0TYG-DPG	Azure Front Door and Azure CDN – Connectivity issues and increased latency	Code or update rollout	Yes	4 h 55 min	East US	Peak traffic increase in the busiest metropolitan areas on Monday morning in the USA initiated the incident due to the reduced capacity caused by regression.
2021-07-07	0_JL-9SG	Service management operation failures – North Europe	Code or update rollout	Yes	14 h 51 min	North Europe	The issue was triggered by a platform update on the servers running the disk management service.
2021-06-29	1V9K-PSZ	Azure Resource Manager – Degraded Performance managing resources	Configuration or operational change	Yes	16 h 6 min	None named	The connection to some of these backend storage endpoints started failing after a maintenance to update their configuration was deployed.
2021-06-14	LL1H-9CZ	Error notifications for service management operations – West US 2	Load or capacity	No	13 h 15 min	West US 2	Additionally, resources hosting this service became unavailable due to a code defect in a driver.
2021-05-20	KN22-39Z	Issues accessing the Azure portal and other Microsoft services	Code or update rollout	Yes	9 h 28 min	None named	The regression introduced lock contention issues which, when triggered, caused some processes on our edge servers to go into a paused state and stop serving traffic for some time.
2021-04-20	HNS6-1SZ	Intermittent 503 errors accessing Azure Portal	Configuration or operational change	Yes	1 h 41 min	UK South, UK West	The Azure portal frontend resources in UK South was taken out of rotation for maintenance the previous day, at 2021-04-19 19:08 UTC.
2021-04-01	GVY5-TZZ	DNS issue impacting multiple Microsoft services	Load or capacity	No	39 min	None named	In this incident, one specific sequence of events exposed a code defect in our DNS service that reduced the efficiency of our DNS Edge caches.
2021-03-18	5LJ1-3CZ	Azure Key Vault – Intermittent failures	Load or capacity	No	3 h 15 min	West Europe, North Europe	This was triggered by a surge of requests to the Data Plane for a specific type of resource which resulted in excessive operations to access the backend storage and over-utilization of network resources as a result of a code defect.
2021-03-15	LN01-P8Z	Authentication errors across multiple Microsoft services	Latent bug, no change named	No	14 h 37 min	None named	This exposed a bug where the automation incorrectly ignored that “retain” state, leading it to remove that particular key.
2021-03-09	8NVQ-HD8	Argentina and Uruguay – Issue Accessing Azure Resources	Hardware, fiber or network device	No	16 min	None named	A regional networking fiber cut resulted in a brief loss of connectivity to Microsoft resources.
2021-02-26	PLWV-BT0	Azure Storage and dependent services – Japan East	Load or capacity	No	6 h 36 min	Japan East	This was due to: Incorrect limits set on the scale unit which allowed more load than desirable to be placed on it.
2021-02-16	ZN8_-VT8	Azure Frontdoor – Europe – Timeouts connecting to resources	Hardware, fiber or network device	No	1 h 30 min	None named	Engineers determined that a backend network device became unhealthy, and traffic was not automatically rerouted.
2021-02-12	CVTV-R80	Azure Cosmos DB connectivity issues affecting downstream services in West US region	Code or update rollout	Yes	5 h 7 min	West US	On February 11, 10:04 UTC (approximately thirteen hours before the incident impact), a Cosmos DB deployment was completed in West US using safe deployment practices; unfortunately, it introduced a code regression that triggered at 23:11 UTC, resulting in the customer impact described above.
2020-12-14	PS0T-790	Azure Active Directory – Authentication errors	Configuration or operational change	Yes	1 h 19 min	None named	The thread contention happened on the scale unit due to a particular combination of requests and a recent change in service topology for the scale unit rolled out previously.
2020-10-27	8SHB-PD0	Azure Active Directory B2C – North Europe / West Europe	Configuration or operational change	Yes	2 h 30 min	North Europe, West Europe	In the North Europe/West Europe regions a configuration change was compounded by a surge in traffic which exceeded the regions’ operational thresholds and required the Azure AD B2C Service to be augmented.
2020-10-19	ZLXD-HT8	Azure Resource Manager – Issues accessing Azure resources via ARM	Configuration or operational change	Yes	3 h 13 min	None named	During integration testing and in the early phases of the rollout, in-line with safe deployment practices, the deployment did not show any problems or regression.
2020-09-28	SM79-F88	Authentication errors across multiple Microsoft services and Azure Active Directory integrated applications	Code or update rollout	Yes	2 h 58 min	None named	In this case, the SDP system failed to correctly target the validation test ring due to a latent defect that impacted the system’s ability to interpret deployment metadata.
2020-09-18	SMSC-FS0	Azure Storage Premium File Shares – East US	Code or update rollout	Yes	8 h 21 min	East US	The incident started when a small number of clients entered an invalid state, triggered by a combination of a routine network maintenance operations which happened on the storage scale unit at the time and a code bug on the client side.
2020-09-14	CSDC-3Z8	Connectivity Issues – UK South	Power or cooling	Yes	11 h 11 min	UK South	It took approximately 120 minutes for the team to diagnose the root cause and begin to remediate the mechanical plant issues, with cooling being restored at 15:45 UTC.
2020-09-03	8KLC-1T8	Network Latency Issue, West Europe	Hardware, fiber or network device	No	8 h 11 min	West Europe	Separately, between 09:21 and 09:26 UTC a significant fiber-cut occurred approximately 5 kilometres from the data centre on one one of the other paths between the data centers.
2020-08-14	9MDM-TT8	Degraded connectivity to Microsoft Services within the Southeast region of the United States	Hardware, fiber or network device	No	1 h 10 min	None named	The initial fiber path incident occurred on 13 Aug 2020 at 18:34 UTC due to a fiber cut causing the path to be removed from Microsoft’s Global Network.
2020-07-18	TTPY-3P0	Azure DNS – Connectivity issues	Configuration or operational change	Yes	55 min	None named	The decommissioning of a legacy (preview) DNS solution inadvertently caused some data streams for Azure DNS recursive resolver service to become out of sync with the resolver state.
2020-07-07	8S8J-9T8	Virtual Machines – Virtual machine unexpected restarts	Code or update rollout	Yes	10 d 13 h 52 min	None named	We determined that an ongoing OS update deployment task inadvertently contained a code configuration error that resulted in a number of previously addressed bug fixes being reverted on a subset of clusters.
2020-07-01	CLCK-LD0	Azure SQL Database – Japan East	Load or capacity	No	1 h 51 min	Japan East	A specific network traffic pattern combined with a networking stack configuration on the SQL Gateway instances triggered an imbalance on the CPU processing of new connection requests.
2020-06-14	PMHH-NS0	Azure Active Directory – Authentication Errors	Load or capacity	No	2 h 40 min	None named	An unexpected increase in traffic volume and resource utilization of infrastructure in the region responsible for acquiring authentication tokens resulted in regional contention which exceeded operational thresholds; resulting in authentication issues for a subset of customers.
2020-06-11	9VHK-J80	Storage – East US	Power or cooling	Yes	2 h 23 min	East US	Engineers determined that an incident during a planned power maintenance activity at the datacenter caused an impact to a single storage scale unit, which then became unhealthy.
2020-06-04	DLZG-7C0	Azure Resource Manager – Failures creating or deleting resources	Configuration or operational change	Yes	9 h 12 min	None named	Due to this wrong setting, the ARM status query for networking service management operations failed, which customers saw as failures when attempting to create or delete networking resources.
2020-05-19	8K76-LZ8	SQL and Open-Source Database Service Management Issues – East US	Latent bug, no change named	No	3 h	East US	The bug was encountered in all the service instances of the region leading to failures and timeouts for management operations.
2020-05-18	SLN3-HD0	Multiple Services – Central India	Power or cooling	No	19 h 49 min	Central India	At 11:25 UTC, a power issue with the regional utility power provider caused a Central India datacenter to transfer to generator power.
2020-04-22	TS66-1C0	Managed Database services – UK South	Configuration or operational change	Yes	4 h 17 min	UK South	The primary instance of the data service became unhealthy preventing some of the service management operations from completing.
2020-04-22	ZK36-9P8	Managed Database services – China North	Configuration or operational change	Yes	4 h 17 min	China North	The primary instance of the data service became unhealthy preventing some of the service management operations from completing.
2020-03-15	SMR4-D90	Service Availability Issue in West Central US	Power or cooling	No	4 h	West Central US	At approximately 20:30 UTC on 15 Mar 2020, an ice storm in the region resulted in a loss of power to both primary and secondary utility power feeds in West Central US.
2020-03-05	SND4-L80	Service Management/Authentication Errors – Azure China	Third party or attack	No	19 h	None named	It caused clients to fail certificate validation, which in turn caused failure in connecting to Azure services.
2020-03-03	9SS0-VT8	Issues connecting to resources in East US	Power or cooling	No	6 h 30 min	East US	Although the cooling system has N+1 redundancy, the automation failure resulted in a significant reduction in cooling air flow.
2020-02-28	DMP0-HT8	Networking Issue in South Central US	Configuration or operational change	Yes	6 h 22 min	South Central US	This configuration triggered a conflict with an existing backend service configuration and caused an increase in the failure rate of requests to the service used for service discovery.
2020-02-22	CT05-PC0	MSA Login Failures	Configuration or operational change	Yes	4 h 41 min	None named	Engineers determined that a server authentication component reached an operational threshold which resulted in increased failures and the unavailability of the service metadata required for successful user sign-in.
2020-02-21	CTH0-HZ8	Networking – Intermittent Connectivity	Configuration or operational change	Yes	2 h 36 min	West Europe, Southeast Asia	The incident was caused by a configuration error pushed to routers in Microsoft Wide Area Network (WAN), in Singapore and Amsterdam.
2020-01-30	0KYQ-PP8	Authentication issues for Microsoft Government Cloud resources	Code or update rollout	Yes	4 h 58 min	None named	There was a code defect in the incremental/delta synchronization pipeline which left the applications in an incorrect state in US Government service regions.
2020-01-25	5TYQ-DC0	SQL Database and dependent services – Service Availability Issues	Configuration or operational change	Yes	10 h 15 min	None named	Engineers determined that a recent maintenance activity did not complete successfully which in-turn caused the gateways to hold an incorrect certificate configuration that effectively blocked connections to the associated SQL resources.
2020-01-24	4_YR-FC8	Cross-Region Connectivity Issue – North America	Configuration or operational change	Yes	1 h 25 min	None named	Incompatible FIB pushes that caused failure on part of the routers resulted in FIB rollbacks.
2020-01-20	0TSQ-TT0	Azure connectivity issues	Hardware, fiber or network device	No	1 h 29 min	None named	Traffic to/from the internet towards Microsoft automatically shifted to other Edge sites in Europe, but the change in path and increase in traffic caused longer latency for some customers.
2019-12-27	4_6S-NC8	Unable to create new resources in Azure Portal	Code or update rollout	Yes	1 h 20 min	None named	Customers were unable to create new resources in the Azure Portal due to a code change that was introduced which caused a key extension to fail, causing a null-reference within the Marketplace blade.
2019-12-12	HKZT-N88	Connectivity issue for Azure Resources in North America	Third party or attack	No	6 h 41 min	None named	Engineers identified a routing protocol metric change within an ISP backbone network, which resulted in network connectivity degradation for a limited subset of Azure customers.
2019-12-11	LTPP-R98	Azure CDN and Azure Kubernetes Service – Service Availability Issue	Third party or attack	No	1 h 24 min	None named	A recent change to Verizon’s deployment pipeline introduced a latent bug that caused some deployment service health notifications to provide incorrect health status.
2019-11-20	archive	Multiple Services – Downstream impact from Azure Front Door	Code or update rollout	Yes	2 h 44 min	None named	Investigation into the faulting behavior revealed that the combination of a sequenced code deployment, a configuration deployment and specific traffic patterns triggered a dormant code bug that instigated the platform to crash.
2019-11-07	archive	Storage – West Europe	Configuration or operational change	Yes	8 h 15 min	West Europe	A bug in this process resulted in backend roles crashing across the scale units participating in the load balancing operations, causing them to become unhealthy.
2019-11-05	archive	Azure Databricks – Unable to connect to workspaces	Load or capacity	No	1 h 15 min	None named	This restart was caused by high CPU usage attributed to other unrelated services sharing the same node.
2019-11-05	archive	Virtual Machines and Storage – West US 2	Latent bug, no change named	No	2 h 57 min	West US 2	A software bug in the code that tracks the progress of those operations caused the processes on the metadata nodes to crash and restart.
2019-11-04	archive	Azure SQL Database – West Europe	Latent bug, no change named	No	6 h 30 min	West Europe	Subsequent investigation by engineers determined this issue was due service requests from an internal Azure group that triggered a bug which caused an excessive number of internally generated operations.
2019-10-30	archive	Storage – West Europe	Latent bug, no change named	No	3 h 35 min	West Europe	In this incident, a unique sequence of circumstances triggered a previously unknown software bug that impacted a single storage scale unit.
2019-10-29	archive	Virtual Machines and Azure Databricks	Configuration or operational change	Yes	6 h 35 min	None named	An incorrect network configuration change was rolled out via an automated workflow which unintentionally targeted multiple production regions.
2019-10-22	archive	Service Availability – West Europe	Configuration or operational change	Yes	3 h 8 min	West Europe	A routine maintenance operation on one of the partitions caused an inconsistency in the partition map due to a bug.
2019-10-21	archive	Service Management Errors – East US 2	Load or capacity	No	13 h 29 min	East US 2	The increased latency triggered retries on the Regional Network control plane service (RNM), which then went into a feedback loop, causing operations to queue up and forced the Regional Network Manager (RNM) into a state where it was not able to recover.
2019-10-21	archive	Storage – West Europe	Configuration or operational change	Yes	5 h 12 min	West Europe	A routine maintenance operation on one of the partitions caused an inconsistency in the partition map due to a bug.
2019-10-18	archive	Authentication issues with Azure MFA in North America	Third party or attack	No	2 h 27 min	None named	This combination of events caused a build-up of unprocessed requests in the MFA service, leading to service degradation and failures in MFA requests.
2019-10-16	archive	Azure Portal	Load or capacity	No	1 h 14 min	UK South	Azure Resource Manager (ARM) is the underlying deployment and management service for Azure, providing the management layer that allows create, update, delete, etc. functions for the platform.
2019-09-30	archive	Storage – Unable to access Azure file share with Azure Active Directory Domain Services joined machines	Configuration or operational change	Yes	2 d 11 h	None named	However, a step was missed in this change which caused Azure Files to fail when authenticating with Azure Active Directory Domain Services.
2019-09-25	archive	Azure Kubernetes Service (AKS) – Provisioning Failures	Configuration or operational change	Yes	7 h 35 min	None named	This update exposed a code defect for the service and a fix for the defect had yet to complete in the impacted regions.
2019-09-16	archive	Azure Front Door Service and Azure CDN	Code or update rollout	Yes	2 d 30 min	None named	Engineers determined that a recent deployment task impacted Key Vault API calls, causing the provisioning failures.
2019-09-11	archive	Australia East – Intermittent Connectivity	Configuration or operational change	Yes	1 h 10 min	Australia East	During a routine configuration update to a single ring, a health check failed, causing the configuration update to automatically roll back.
2019-08-28	archive	Azure Email Alerts	Load or capacity	No	5 h 13 min	None named	During scale up operations the service became unresponsive due to logging operations exceeding thresholds.
2019-08-23	archive	Service Management Operations – West/North Europe	Load or capacity	No	4 h 26 min	North Europe, West Europe	This should have initiated a clearing process which attempts to recover additional memory when thresholds are reached.
2019-08-16	archive	Azure Services – South Central US	Configuration or operational change	Yes	7 h 20 min	South Central US	However, an error in fiber trunk validation resulted in production impacting connectivity loss.
2019-08-14	archive	USGov Iowa – Service Availability and Downstream Impact	Load or capacity	No	8 h 35 min	US Gov Iowa, US Gov Virginia	A secondary issue was detected on review that was causing the build-up of the number of nodes requiring non-automated or manual repair.
2019-08-09	archive	Azure Portal – Issues Loading Dashboard Tiles	Code or update rollout	Yes	3 h 10 min	None named	The issue was caused by a code change that introduced a bug in an underlying API that the affected experiences relied on.
2019-08-08	archive	Azure CDN – Connectivity Issues	Configuration or operational change	Yes	4 h 55 min	East US, East US 2	Engineers determined that a network update to add new peer servers to the US East region caused connections to fail between Akamai CDN and Azure resources.
2019-07-30	archive	Issues logging in to the Azure Portal with a Microsoft Account	Configuration or operational change	Yes	1 h 24 min	None named	It was determined that combination of factors including a device mismatch and code bug, resulted in the active device becoming unstable.
2019-07-08	archive	Azure Active Directory – Password Changes	Code or update rollout	Yes	4 h 23 min	None named	Engineers determined that a recent deployment of a certificate caused backend instances responsible for password change functionality to reject the password change operation.
2019-07-04	archive	Connectivity Issues – UK South	Load or capacity	No	10 h 7 min	UK South	During the last two weeks of June, the customer traffic on a single storage scale unit in the UK south region had increased more quickly than normal, and the automatic load balancing system had responded by beginning to shift load to other scale units.
2019-07-03	archive	Azure Monitoring (Diagnostic logs, Autoscale, Classic Alerts (v2))	Configuration or operational change	Yes	6 h	None named	As part of service engineering improvements, a configuration change was incorrectly applied to the underlying KeyVault resources which are used by Azure Monitor’s management services (Autoscale, Classic Alerts, Diagnostic Settings) during start up.
2019-07-02	archive	Azure Services – Intermittent Service Availability Issues	Hardware, fiber or network device	No	3 h	None named	One of the network devices in San Jose had a hardware grey failure at 19:20 UTC, causing traffic going to one of Microsoft peer networks to experience intermittent failures.
2019-06-14	archive	Virtual Machines and Virtual Networks (Management) – North Europe	Configuration or operational change	Yes	5 h 13 min	North Europe	The rollout of the bad configuration information to the SLB servers was not automatically stopped and rolled back by the Azure Deployment system as the SLB monitoring and alerting components did not determine this was an incorrect and undesirable configuration.
2019-05-22	archive	Service Management Operations – West Europe	Latent bug, no change named	No	5 h 50 min	West Europe	Prolonged operational delays triggered a RNM bug which caused the primary replica to re-build on two occasions.
2019-05-13	archive	Network Connectivity – Increased Latency	Latent bug, no change named	No	6 h 28 min	None named	The impact was the result of inconsistent data replication in a networking infrastructure service.
2019-05-02	archive	Network Connectivity – DNS Resolution	Configuration or operational change	Yes	3 h 6 min	None named	A misconfiguration in the parameters of the automation being used to make the change resulted in an incorrect delegation for the name server under maintenance. 2) As an artifact of automation from prior maintenance, empty zone files existed on servers that were not the intended target of the assigned delegation.
2019-05-02	archive	Azure Map	Configuration or operational change	Yes	6 h 25 min	None named	Upon investigation, engineers found that the authentication application was inadvertently removed in error during regular maintenance operations.
2019-04-19	archive	Availability degradation for Azure DevOps	Configuration or operational change	Yes	11 h 50 min	None named	During a planned maintenance event for Azure Front Door (AFD), a configuration change caused network traffic to be incorrectly advertised.
2019-04-16	archive	Networking Degradation – Australia Southeast / Australia East	Third party or attack	No	50 min	Australia Southeast, Australia East	The issue stemmed from a routing anomaly due to an erroneous advertisement of prefixes received via an ExpressRoute circuit to an Internet Exchange (IX).
2019-04-12	archive	Cognitive Services	Code or update rollout	Yes	9 h 40 min	West Europe, West Central US	Engineers determined a recent deployment introduced a software regression, manifesting in increased latency across two regions.
2019-04-09	archive	Virtual Machines – North Central US	Configuration or operational change	Yes	8 h 41 min	North Central US	This situation was designed to be handled with fallback to our existing data path, but an additional bug led to failure in the fallback path and resulted in in VM reboots.
2019-03-29	archive	SQL Database	Code or update rollout	Yes	5 h 20 min	East US, UK South, West US 2	Deployments in Azure follow the Safe Deployment Practice (SDP), which aims to ensure deployment related incidents do not occur in many regions at the same time.
2019-03-28	archive	Data Lake Storage / Data Lake Analytics	Configuration or operational change	Yes	5 h 13 min	East US 2, West Europe, Japan East	An engineer made changes to the global partition.config file for the identified regions and triggered deployment using the process described above.
2019-03-27	archive	Service Management Failures – West Europe	Load or capacity	No	1 d 2 h 10 min	West Europe	Root Cause: Regional Network Manager (RNM) is a core component of the network control plane in Azure.
2019-02-27	archive	USGov Virginia – Service Availability	Power or cooling	Yes	2 h 12 min	US Gov Virginia	During routine electrical equipment maintenance at a datacenter, the equipment responsible for load transfer to our redundant power source failed, causing temporary power loss to a subset of racks and devices within the US Virginia data center.
2019-02-22	archive	Virtual Machines (Classic)	Code or update rollout	Yes	3 h 32 min	None named	Engineers established that a platform service update introduced this regression that surfaced only at high incoming traffic volume.
2019-02-20	archive	SQL Services – West Europe	Latent bug, no change named	No	7 h 35 min	West Europe	Logic that selects a ring, a unit of capacity within a region, to place a service instance during creation or SLO change could incorrectly pick the same overloaded ring for incoming placement operations.
2019-02-18	archive	Erroneous Browser Warning – Azure Germany Portal	Third party or attack	No	3 h 10 min	None named	The URL login.microsoftonline.de was incorrectly classified as an unsafe site due to an operational error, resulting in impact.
2019-02-11	archive	Azure Kubernetes Service – East US	Configuration or operational change	Yes	7 h 5 min	East US	Engineers determined that during a recent deployment of new capacity to the backend services responsible for managing deployments and maintenance on customer clusters encountered an error.
2019-02-08	archive	Azure IoT Hub	Latent bug, no change named	No	5 h 56 min	None named	Engineers found that one of the SQL queries automatically started using a bad query plan causing the SQL DB to start consuming a significantly large percentage of database transaction units (DTUs).
2019-01-30	archive	Intermittent Network Related Timeouts – West US	Code or update rollout	Yes	2 h 40 min	West US	A network device in the US West region experienced a FIB/Linecard problem during a routine firmware update.
2019-01-29	archive	Network Infrastructure Event	Third party or attack	No	3 h 10 min	None named	Root Cause: An external DNS service provider experienced a global outage after rolling out a software update which exposed a data corruption issue in their primary servers and affected their secondary servers, impacting network traffic.
2019-01-10	archive	Storage and Dependent Services – UK South	Hardware, fiber or network device	No	16 h 11 min	UK South	Unfortunately in this incident, the unique nature of the problem, combined with the number of subsystems affected and the interactions between them, led to a longer than usual time to root cause and mitigate.
2019-01-08	archive	Azure DevTest Labs – Virtual Machine Error Message	Code or update rollout	Yes	1 d 8 h 22 min	None named	Engineers determined that an issue within a recent Azure Portal UI deployment task caused impact to customer resource error messaging and operations.
2018-12-14	archive	Networking – UK West	Hardware, fiber or network device	No	8 h 55 min	UK West	Engineers determined that an external networking circuit experienced a hardware failure impacting a single fiber in this region.
2018-12-04	archive	Networking – South Central US	Configuration or operational change	Yes	2 h 4 min	South Central US	Two network devices in the South Central US region received an incorrect configuration during an automated process to update their configuration and firmware.
2018-11-27	archive	Multi-Factor Authentication	Not determined	No	20 min	None named	This outage was caused by a Domain Name System (DNS) failure which made the MFA service temporarily undiscoverable and a subsequent traffic surge resulting from the restoration of DNS service.
2018-11-26	archive	Virtual Network – UK South and UK West	Hardware, fiber or network device	No	5 h 37 min	UK South, UK West	A 16 minute hardware failure on a WAN router caused a large amount of traffic to failover from the primary path out of the region to the backup path, causing increased congestion on the backup path.
2018-11-19	archive	Issues connecting to Azure resources in Europe, Asia and the Americas regions using Multi-Factor Authentication	Code or update rollout	Yes	13 h 59 min	None named	The second root cause is a race condition in processing responses from the MFA backend server that led to recycles of the MFA frontend server processes which can trigger additional latency and the third root cause (below) on the MFA backend. 3.
2018-11-11	archive	Storage – West US	Third party or attack	No	10 h 7 min	West US	It started when a route configuration at one of the regional internet service providers caused traffic to get re-routed incorrectly and drop.
2018-10-24	archive	Networking in West US	Hardware, fiber or network device	Yes	1 h 23 min	West US	A network device connecting a datacenter in the West US region experienced a fault during routine fiber maintenance.
2018-10-16	archive	Azure Service Availability – France Central	Power or cooling	Yes	2 h 48 min	France Central	While working on the system, the maintenance engineer inadvertently triggered the fire alarm for this Colo, which in normal circumstances would have alerted staff, but would not have caused any impact to running services in the Colo.
2018-10-13	archive	Storage – East US	Load or capacity	No	5 h 50 min	East US	Unexpectedly, a small number of the failed roles did not recover automatically.
2018-10-11	archive	App Service – East Asia	Latent bug, no change named	No	26 min	East Asia	The Microsoft Azure team identified the issue was due to a dependency that the Web App service takes on Azure Storage.
2018-10-08	archive	Service Bus – East US and West US	Code or update rollout	Yes	1 d 4 h	East US, West US, East US 2	On this incident, that condition was triggered when the Service Bus VMs received the monthly OS Patch.
2018-10-02	archive	ExpressRoute Circuit – Australia Southeast	Hardware, fiber or network device	No	3 h 45 min	Australia Southeast	It was identified that an upstream physical port experienced a partial failure causing the connection between the ExpressRoute routers and the Microsoft global network to intermittently drop packets.
2018-09-26	archive	Multiple Services – Southeast Asia	Hardware, fiber or network device	No	2 h 36 min	Southeast Asia	The flapping behavior of the console ports triggered a bug in the console line driver of the Operating System kernel running on the 8 row-level network switches, and caused a correlated failure of all 8 row-level switches.
2018-09-15	archive	Virtual Machines – Metrics Unavailable	Configuration or operational change	Yes	2 d 16 h 5 min	None named	When the VIP was failed over, the agent did not properly detect and re-establish connectivity to the functioning instance during the maintenance period.
2018-09-15	archive	Metrics Missing – Germany	Configuration or operational change	Yes	2 d 16 h 5 min	None named	When the VIP was failed over, the agent did not properly detect and re-establish connectivity to the functioning instance during the maintenance period.
2018-09-05	archive	Azure Active Directory – Multiple Regions	Code or update rollout	Yes	4 d 20 h 50 min	East US 2	A recent change to the Azure VM platform resulted in interference with the HTTP settings used by the Azure Active Directory (AAD) proxy service.
2018-09-04	archive	South Central US	Power or cooling	No	not stated	South Central US	By design this sag triggered the chillers to power down and lock out, to protect this equipment.
2018-05-03	archive	Multiple Services – West Central US	Configuration or operational change	Yes	2 h 18 min	West Central US	In this incident, the Management ACLs were incorrectly applied in some network switches due to the differences in how ACLs are interpreted between different operating system versions for the network switches.
2018-04-26	archive	App Service – Canada Central	Load or capacity	No	43 min	Canada Central	The root cause for the issue was that there was a significant increase in HTTP traffic to certain sites deployed to this region.
2018-04-15	archive	Issues Performing Service Management Operations – Australia East/Southeast	Configuration or operational change	Yes	6 h 20 min	Australia East, Australia Southeast	A storage infrastructure configuration change as part of a new deployment resulted in an authentication failure.
2018-04-09	archive	Azure Active Directory B2C – Multiple Regions	Code or update rollout	Yes	2 h 8 min	None named	Due to a regression introduced in a recent update in our data storage service that was applied to a subset of our replicated data stores, data objects were moved to an incorrect location in a single replicated data store in each of the two impacted scale units.
2018-03-20	archive	App Service and App Service Linux – Multiple Regions	Code or update rollout	Yes	2 h 58 min	None named	The root cause of the issue was a software bug introduced in a specific API call during a recent platform update.
2018-03-19	archive	SQL Database – West Europe	Code or update rollout	Yes	23 h 30 min	West Europe	The specific point was due to a combination of factors & heavy load on the region, a bug causing an increase in the size of the image being downloaded, and a pre-existing configuration mismatch on a small set of scale units in the region.
2018-03-01	archive	Microsoft Azure Portal	Load or capacity	No	7 h 20 min	West Europe, North Europe, UK South	Upon investigation, engineers determined that the scale out operation in North Europe did not complete successfully due to ongoing deployment in that region.
2018-02-20	archive	Multiple Services – UK South	Configuration or operational change	Yes	3 h 14 min	UK South	After the detailed investigation, engineers confirmed that the Datacenter power hardware operated as expected, without any unexpected gap in power supply, as this issue was initiated by the commands executed during build-out.
2017-10-07	archive	Infrastructure issue impacting multiple Azure services – Australia East	Power or cooling	Yes	27 min	Australia East	During a planned facility power maintenance activity, power was removed from a single feed.
2017-09-29	archive	Storage Related Incident – North Europe	Power or cooling	Yes	6 h 48 min	North Europe	When suppression was triggered, it initiated the automatic shutdown of Air Handler Units (AHU) as designed for containment and safety.
2017-09-04	archive	ExpressRoute \ ExpressRoute Circuits – Washington DC	Configuration or operational change	Yes	5 h 49 min	None named	A routine maintenance was being conducted on the Microsoft Network in the Washington DC area.
2017-05-18	archive	Storage Latency – West Europe	Configuration or operational change	Yes	13 h 14 min	West Europe	To increase capacity on aggregation routers, a routine maintenance was performed to deploy configuration updates.
2017-05-12	archive	Network Infrastructure – East US	Hardware, fiber or network device	No	35 min	East US	A failed line card on a network device combined with fiber damage to a second device caused customer impairment.
2017-05-10	archive	Intermittent Authentication Failures due to Underlying Azure Active Directory issues	Configuration or operational change	Yes	40 min	None named	Unfortunately, this process was not closely followed resulting in an unintentional configuration change being rolled out to the Azure Active Directory production services.
2017-05-04	archive	Virtual Machines – Japan East	Latent bug, no change named	No	40 min	Japan East	Unfortunately in this incident the combination of the above and a higher than normal request load on the cluster, exposed a rare software bug which resulted in the failure of storage roles on several additional nodes.
2017-03-25	archive	Intermittent Authentication Failures due to Underlying Azure Active Directory Issue	Latent bug, no change named	No	3 h 12 min	None named	This caused the backend of the STS to become overwhelmed and resulted in timeouts and requests being dropped.
2017-03-23	archive	Data Lake Analytics and Data Lake Store, East US 2	Configuration or operational change	Yes	2 h 23 min	East US 2	A misconfiguration in one of the microservices that ADLS depends on caused the ADLS microservices to not serve requests after they, or the instances they resided on restarted (which restart is part of regular maintenance process).
2017-03-22	archive	Increased latency accessing Azure resources	Power or cooling	No	1 h 22 min	East US	Due to severe weather in the Atlanta, Georgia, one of the 3rd party peering sites experienced an infrastructure event resulting in loss of cooling.
2017-03-21	archive	Storage and Virtual Machines – West Europe	Hardware, fiber or network device	No	not stated	West Europe	Due to the failure of an optical line card, network operational thresholds were reduced in West Europe.
2016-12-11	archive	for Network Infrastructure in West Europe	Hardware, fiber or network device	No	1 h 16 min	West Europe	We encountered a software issue on our network routers that caused routing calculations to take longer than expected during a fiber issue in West Europe.
2016-12-07	archive	for Storage in North Europe affecting Multiple Services	Latent bug, no change named	No	2 h 48 min	North Europe	The system then enters into failsafe mode resulting in a pause of any data deletion actions on data tagged for deletion (Garbage Collection) until the replicas are again available, the system exits failsafe mode, and the service is fully recovered.
2016-11-30	archive	Traffic Manager impacting Multiple Services	Configuration or operational change	Yes	20 min	None named	A misconfiguration resulted in inbound routing failure through one of the devices critical to the path of the Traffic Manager services.
2016-11-21	archive	Microsoft Azure Portal, Errors using Azure Resource Manager to create Virtual Machines	Code or update rollout	Yes	6 h 5 min	None named	Unfortunately the change had a side effect and caused a failure while validating the location of VM at a creation.

“archive” links open the Internet Archive capture where we found a review that is no longer on Microsoft’s page. Dashes inside quotes are shown as commas.

Is Azure down? How to check

A history cannot tell you about right now, but the reviews show where Microsoft actually communicates during an incident.

Start with Azure Service Health in the portal. Microsoft’s documentation says incidents are communicated to affected subscriptions through Service Health, and that the PIR for a narrower incident goes only to affected customers there. Set up Service Health alerts to email, SMS or a webhook into your PSA.
Then check the public status page. azure.status.microsoft is used for three scenarios only: broad impact across multiple services in a full region or several regions, an issue that blocks access to the portal or Service Health, or broad impact Microsoft cannot yet scope. A quiet status page does not mean your subscription is unaffected.
Look for the Tracking ID. Every review carries one (such as YKYN-BWZ). It ties the Service Health notice, the status page and the final review together, and you can open a review directly with azure.status.microsoft/en-us/status/history/?trackingId=ID.
Expect two reviews. Microsoft says it endeavors to publish a preliminary PIR within 3 days of mitigation and a final PIR after its internal retrospective, generally within 14 days.
Know what the page leaves out. Microsoft 365 has its own status channels; 21 of the 219 Azure reviews mention Microsoft 365 or Office 365, usually because a shared dependency such as Entra ID or Front Door failed.

How Microsoft decides what gets a public review

The counts above depend on publishing rules that changed twice, and Microsoft states them at the top of the history page.

Until Nov 19, 2019The history page showed recent communications, including preliminary notes. Older items survive only in archive captures.

Nov 20, 2019PIRs for all issues about which Microsoft communicated publicly.

June 1, 2022 onwardPIRs for broad issues only (“Scenario 1”); other reviews go privately to affected customers. Each entry is kept 5 years.

Two consequences matter for anyone counting outages. First, the yearly count fell from 28 reviews in 2020 to 15 in 2023, 14 in 2024, 13 in 2025 and 10 so far in 2026. Because the rule narrowed in June 2022, that drop says nothing on its own about reliability. Second, the page is not append-only: Microsoft removes Scenario 3 entries after sending the final review through Service Health, and it removes everything after five years. Google publishes under a similar rule, as our Google Cloud outage history shows.

What this means for MSPs

Most Azure outages start with a change, so watch Microsoft’s change cadence. 58% of reviews trace back to a configuration push, rollout or maintenance step. Global services such as Front Door, Entra ID and Resource Manager have failed everywhere at once: 45 reviews in those families name no single region. For client workloads, that argues for a second path that does not share the failing service: an alternate DNS or CDN route in front of Front Door, and break-glass admin accounts that do not depend on a single sign-in path.

Availability Zones help with power, not with global services. 11 of the 14 power or cooling reviews since June 2022 describe a single-zone event, and several say zone-redundant services, such as zone-redundant Azure SQL Database, kept running. Two did not stay in one zone: the August 2022 West US 2 utility outage hit the whole region, and the May 2026 storms reached two zones. And 42% of reviews name no single region, and no zone or region choice protects against a global control-plane fault. Match the design to the risk, and price it against the downtime terms in each provider SLA, which our 99.9% uptime calculator breaks down.

Wire Service Health into your ticketing, per tenant. Since June 2022 most incident reviews never reach the public page. If you manage many tenants, each one needs Service Health alerts routed to your PSA, or you will learn about incidents from your clients. Keep the Tracking ID in the ticket so you can attach the final review to your client report.

Plan for the long tail. The median window is 5 h 45 min, but power events run a median 8 h 32 min, and recovery of dependent services often continues after Microsoft declares mitigation. Runbooks that assume a one-hour blip will fail in exactly the incidents that matter.

Frequently asked questions

Is there an Azure outage today?

This page is a history, not a live monitor. For current status, check azure.status.microsoft, which Microsoft uses only for broad issues across multiple services and regions, and Azure Service Health in the portal, where Microsoft sends most incident notices to affected subscriptions. The most recent review in our casebook covers a networking gateway incident on September 30, 2026.

What was the biggest Azure outage?

By impact window, the longest review in our casebook is a July 2020 virtual machine restart issue that ran 10 d 13 h 52 min. By reach, the Azure Front Door incident of October 29, 2025 stands out: it lasted 8 h 24 min and hit customers and Microsoft services worldwide. The July 18, 2024 Central US storage incident ran 1 d 20 min.

What causes Azure outages?

In 127 of the 219 reviews (58%), the incident began with something Microsoft changed: a configuration push, a code or OS update, maintenance work, or a migration. Power and cooling failures account for 25 reviews, hardware and fiber faults for 22, and load surges for 23.

How long do Azure outages last?

The median impact window across 215 reviews with a stated start and end is 5 h 45 min. For the 78 reviews on Microsoft’s current history page it is 8 h 24 min. Power and cooling events run longest, with a median of 8 h 32 min.

Which Azure region has the most outages?

West Europe is named in 34 of the 219 reviews, more than any other region. But 92 reviews (42%) name no single region because the fault was global or spanned many regions, as with Azure Front Door.

How do I check Azure outage history?

Microsoft’s status history page lists post incident reviews for broad issues and keeps each one for five years, so entries older than late 2021 have dropped off. We rebuilt the older record from Internet Archive captures. Our full casebook of 219 reviews can be downloaded below.

Download the data. azure-outage-pir-casebook-2016-2026.csv (CSV). Licensed under CC BY 4.0: free to reuse with attribution to The Uptime Report.

Methodology

Sources. Microsoft Azure status history, every entry from the page’s own history endpoint (statushistoryapi, all services, all regions, all dates), pulled on October 13 and October 29, 2026; 101 Internet Archive captures of the history page at azure.microsoft.com (2016 to 2019), status.azure.com (2019 to 2023) and azure.status.microsoft (2022 to 2026), spaced at least 20 days apart; Microsoft Learn, “Azure status overview” (status page criteria).

What counts as a review. An entry titled RCA or Post Incident Review, or whose text contains a final root-cause section (“Root cause:” or “What went wrong and why?”). Preliminary notes without a root cause, and entries saying only that analysis would follow, are excluded. Entries are deduplicated by Tracking ID, or by date and normalised title before Microsoft added Tracking IDs in 2019 to 2020; one duplicate RCA (November 19, 2018 MFA) was removed. 141 of the 219 reviews come only from archive captures. Coverage before November 2021 is incomplete because captures exist for some months only and older pages showed a short window.

Root-cause coding. One category per review, for the event that started the incident, assigned by reading the root-cause section: configuration or operational change (including maintenance, migrations, decommissioning and capacity work), code or update rollout (including OS, firmware and certificate deployments), latent bug with no change named, load or capacity, power or cooling, hardware, fiber or network device, third party or attack (ISPs, vendors, DDoS), or not determined. “Began with a Microsoft change” is true for the first two categories and for physical events Microsoft says started during its own maintenance. Where a customer action triggered a latent bug (Front Door, October 29, 2025), the review is coded as a latent bug and not as a Microsoft change. Judgement calls are ours; the codes are in the CSV.

Windows and regions. The impact window is the first stated window in the review’s opening summary (“Between … and …”), converted to UTC (EST, EDT and US Central times for Azure Government; China Standard Time, UTC+8, for Azure in China). 4 reviews state no end time. Regions are Azure region names found in the title and opening summary.

Limitations. Microsoft decides what gets a public review, and the rule changed in 2019 and 2022, so yearly counts measure publishing as much as reliability. The casebook says nothing about incidents communicated only through Service Health. Not advice.

Cite as:The Uptime Report. "Azure Outage History: 127 of 219 Microsoft Post Incident Reviews Began With Microsoft's Own Change." October 2026. https://theuptimereport.com/azure-outage/

References

Microsoft Azure, Azure status history (all entries via the page’s history endpoint). Accessed October 2026.
Microsoft Learn, Azure status overview (status page scenarios and PIR publishing). Accessed October 2026.
Internet Archive, captures of azure.microsoft.com/en-us/status/history/, 2016 to 2019. Accessed October 2026.
Internet Archive, captures of status.azure.com/en-us/status/history/, 2019 to 2023. Accessed October 2026.
Internet Archive, captures of azure.status.microsoft/en-us/status/history/, 2022 to 2026. Accessed October 2026.
Microsoft Azure, PIR YKYN-BWZ, Azure Front Door, Connectivity issues across multiple regions, October 29, 2025. Accessed October 2026.
Microsoft Azure, PIR QNBQ-5W8, Azure Front Door, Access issues in multiple regions, October 09, 2025. Accessed October 2026.
Microsoft Azure, PIR 1K80-N_8, Storage, Impact to multiple services in Central US, July 18, 2024. Accessed October 2026.
Microsoft Azure, PIR GHRP-84G, Multiple services, Power/cooling issues in West US 2, May 29, 2026. Accessed October 2026.
Microsoft Azure, PIR _SVS-5_G, Power event impacting multiple services, West US, February 07, 2026. Accessed October 2026.
Microsoft Azure, PIR FNJ8-VQZ, Virtual Machines, Managed identities for Azure resources, and dependent services, Service management issues in multiple regions, February 02, 2026. Accessed October 2026.
Microsoft Azure, PIR VN11-JD8, Multi-service outage, Asia-Pacific Area, February 07, 2023. Accessed October 2026.
Microsoft Azure, PIR LN01-P8Z, Authentication errors across multiple Microsoft services, March 15, 2021. Accessed October 2026.

Research library

More original data reports from The Uptime Report. Every report includes its methodology and a free CSV download. Browse all research

Threats and breaches

Hypervisor Vulnerabilities
Hypervisor CVEs vs exploitation
DMARC Adoption Statistics 2026
DMARC enforcement, 15,000 domains
RMM Vulnerabilities and Remote Access Flaws
RMM and remote access flaws in KEV
Identity Theft Statistics 2026
ID theft per 100K by state and type
Scam Statistics 2026
FTC fraud losses by channel and age
VPN Vulnerabilities by Vendor
VPN gateway KEV and CVEs by vendor
MFA Statistics 2026
MFA methods across 2,571 services
Password Statistics 2026
12,674 passwords tested against HIBP
Ransomware Groups 2026
Most active ransomware groups, ranked
Ransomware Statistics 2026
Leak-site victims by month since 2021
Malicious npm Packages
Malicious npm packages, day by day
Cybersecurity Statistics 2026
70 sourced stats, every number traced
Zero-Day Statistics
Every tracked zero-day since 2014
Phishing Statistics 2026
Four phishing measures, one evidence board
Patch Tuesday Statistics 2026
Every Microsoft CVE since 2021
Disaster Declarations by State
FEMA data for continuity planning
Data Breach Statistics 2026
980 breaches in Have I Been Pwned
Ransomware Initial Access Vectors
CISA advisories coded by entry technique
CVE Statistics 2026
Vulnerabilities published per year, NIST NVD
How Long Do Companies Take to Report a Data Breach?
1,675 Washington notices
Known Exploited Vulnerabilities
The CISA KEV catalog analyzed
Healthcare Data Breach Report 2026
HHS OCR breach portal scorecard
Ransomware Reported to the FBI
Five-year IC3 trend

Infrastructure and uptime

Microsoft 365 Market Share 2026
Who runs email: Microsoft vs Google
CrowdStrike Outage
July 19, 2024 outage, minute by minute
Data Center Electricity Prices 2026
Power prices vs data center load, by state
Average Internet Bill 2026
Home internet prices by speed and state
Search Engine Market Share 2026
Search share since 2009, by country
ChatGPT Market Share 2026
AI chatbot referral share, every tracker
Google Cloud Outage History
Google Cloud incidents by product, 2013 on
Data Center Water Usage 2026
Water by site, company and drought
AI Energy Consumption 2026
Big Tech electricity vs US demand
SSD Prices 2026
NAND price cycle from makers’ filings
RAM Prices 2026
DRAM prices from producers’ filings
Domain Name Statistics 2026
Domains by TLD, renewals, registrars
Linux Market Share 2026
Linux desktop share, every headline traced
GitHub Outages
GitHub incidents by month since 2020
Cloudflare Outage History
Every Cloudflare outage post-mortem
Starlink Statistics 2026
Satellites, subscribers, coverage, outages
Internet Access Statistics 2026
Home internet gaps by state and group
SQL Server End of Life
SQL Server support countdown + CVEs
Windows 11 Market Share 2026
Windows 10 vs 11 share by country
Cloud Computing Statistics 2026
Hyperscaler revenue and capex, SEC data
AWS Outage History
Every AWS Post-Event Summary since 2011
Data Centers by State 2026
Sites, jobs, power for every state
Data Center Statistics 2026
Data center power, spending, jobs
99.9% Uptime
Uptime calculator and 35 real SLAs
Power Outage Statistics by State
Outage hours by state, EIA data
Cost of Downtime
Revenue per hour for 3,001 public companies
Windows Server End of Life
Support dates and CVEs per server version

Regulation and disclosure

FedRAMP Statistics 2026
FedRAMP authorizations, GSA data
Item 1C Cybersecurity Disclosures
What 600 10-Ks say in Item 1C
CMMC Certification Statistics 2026
CMMC demand vs assessor capacity
Data Brokers List 2026
728 brokers across three state registries
SEC Cybersecurity Incident Disclosures
Every 8-K Item 1.05 filing
HIPAA Enforcement Tracker
Every OCR penalty and settlement

Workforce and pay

AI at Work Statistics 2026
Worker AI use: ever, weekly, daily, by job
Network Engineer Salary 2026
Network engineer vs admin pay, BLS
IT Manager Salary 2026
IT manager pay by industry, BLS OEWS
Software Engineer Salary 2026
Developer pay by metro, BLS OEWS
H-1B Statistics 2026
H-1B lottery, employers, and wages
AI Layoffs 2026
AI-blamed job cuts, sourced to filings
Help Desk Salary 2026
Help desk hourly pay, BLS OEWS
Cybersecurity Salary 2026
Security pay percentiles, BLS OEWS
Women in Tech Statistics 2026
Women’s share of tech jobs since 2011
IT Unemployment Rate 2026
Tech vs national jobless rate, monthly
Tech Job Postings 2026
Tech postings vs 2020, by role and country
Tech Layoffs 2026
Tech layoffs from state WARN notices
Remote Work Statistics 2026
Telework by job, industry, and state
Highest Paying Cities for IT Jobs 2026
Metro pay by role, BLS OEWS
The Tech Job Market in 2026
Openings, quits, hires, layoffs
IT Salaries by State 2026
Pay matrix for four IT roles
IT and Cybersecurity Jobs Outlook 2026
BLS employment projections

MSP market and spending

Microsoft 365 Price Increase 2026
Every M365 price change, vs inflation
Computer Prices 2026
Computer price indexes and HS 8471 imports
MSP Market Size 2026
Managed services market, built from Census
Small Business AI Adoption 2026
AI use by firm size, sector, state, Census
Cyber Insurance Statistics
Cyber insurance market, NAIC 2015-2024
IT Spending by Industry
IT investment by industry, BEA
IT Services Industry Growth 2026
Census revenue by service industry
IT Hourly Rates 2026
Hourly IT labor rates, GSA contracts
VoIP Statistics 2026
Business VoIP vs landlines, FCC
MSP Industry Statistics 2026
Jobs, wages, and firms, BLS QCEW
Federal IT Spending 2026
IT services contracts, USAspending
IT Services Firms by State
Census business patterns atlas

Comments

2 responses to “Azure Outage History: 127 of 219 Microsoft Post Incident Reviews Began With Microsoft’s Own Change”

October 29, 2026

Data Center Water Usage 2026: Every Disclosed Site

[…] Azure Outage HistoryEvery Azure PIR, coded by root cause […]

October 29, 2026

Google Cloud Outage History: 1,472 Incidents Mapped

[…] Google’s public incident file, status.cloud.google.com/incidents.json, only holds a rolling window of recent incidents, so no single download shows the history. We combined 91 readable monthly Internet Archive captures of that file since 2015 with the live copy from October 29, 2026, keeping the latest version of each incident. Counts for 2022 to 2025 match Google’s own per-product history pages exactly. We then read the root-cause text of every high-severity incident since 2018. It is the same approach behind our AWS outage history and the companion Azure outage casebook. […]

Azure Outage History: 127 of 219 Microsoft Post Incident Reviews Began With Microsoft’s Own Change

The biggest Azure outages, in Microsoft’s words

Azure Front Door, Connectivity issues across multiple regions

Azure Front Door, Access issues in multiple regions

Storage, Impact to multiple services in Central US

Multiple services, Power/cooling issues in West US 2

Power event impacting multiple services, West US

Virtual Machines, Managed identities for Azure resources, and dependent services, Service management issues in multiple regions

Multi-service outage, Asia-Pacific Area

Authentication errors across multiple Microsoft services

Azure outages in 2026 so far

What causes Azure outages?

Which Azure regions have the most outages?

How long Azure outages last

Every Azure post incident review in one table

Is Azure down? How to check

How Microsoft decides what gets a public review

What this means for MSPs

Frequently asked questions

Is there an Azure outage today?

What was the biggest Azure outage?

What causes Azure outages?

How long do Azure outages last?

Which Azure region has the most outages?

How do I check Azure outage history?

Methodology

References

Research library

Comments

2 responses to “Azure Outage History: 127 of 219 Microsoft Post Incident Reviews Began With Microsoft’s Own Change”

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