Microsoft Azure experienced a widespread outage in its West Europe cloud region on November 5, after a data center suffered a “thermal event” that triggered automatic shutdowns to protect hardware. The incident affected multiple Azure services, disrupting both enterprise and public sector users across the Netherlands and neighbouring areas.
The event caused a subset of storage scale units in a single availability zone to go offline. While this issue was isolated, other services on these units led to ripple effects across the region. Dutch transport services, including the national rail operator, reported delays and service interruptions during the outage, illustrating the extent to which critical infrastructure relies on cloud services.
The outage began around 17:00 UTC and affected numerous services, including Virtual Machines, Azure Database for PostgreSQL/MySQL Flexible Servers, Azure Kubernetes Service, Storage, Service Bus, and VM Scale Sets. Microsoft confirmed that cooling system failures triggered the protective shutdowns, a safeguard designed to prevent damage from overheating.
Microsoft engineers worked quickly to restore affected units and bring impacted services back online. In their history status report Microsoft stated, “We determined that a thermal event in West Europe caused a power sag that led to all cooling units going offline, resulting in elevated temperatures in the data center. This temperature spike triggered the clusters’ built-in safety mechanisms, leading to service disruption for VMs and dependent services.”
Technical analyses highlight that the incident underscores the importance of redundancy and proactive monitoring across cloud regions. While the shutdowns were necessary to protect hardware, Microsoft revealed vulnerabilities in regional dependencies and emphasized the need for businesses to account for potential cascading failures in their cloud architecture.
This outage further highlighted lessons learned for storage redundancy and regional risk mitigation to minimize future impacts. The incident is a reminder of the challenges cloud providers face in maintaining uninterrupted service and the importance for organizations to plan for unexpected disruptions in critical cloud infrastructure.