RESOLVED: We are investigating an issue where customers may experience timeouts, service degradations, errors, and elevated latencies across multiple products in the us-west1 region.

Incident began at 2026-08-20 08:40 and ended at 2026-08-20 12:20 (all times are US/Pacific ). Incident Report Summary On Thursday, 20 August 2026, from 08:00 to 10:22 US/Pacific (15:00 to 17:22 UTC), multiple Google Cloud services in the us-west1 region experienced elevated latency, provisioning failures, increased error rates, and widespread service degradations for a total duration of 2 hours and 22 minutes. The incident impacted a wide range of core services — including Persistent Disk, Google Kubernetes Engine, Google Compute Engine, Cloud Run, Google Cloud Bigtable, Cloud Storage, and Identity and Access Management — across both control plane operations and data plane requests. We sincerely apologize for the disruption this incident caused to your business operations and critical workloads. We recognize the vital role Google Cloud plays in supporting your organization, and we deeply regret the impact on your business operations and critical workloads. Engineering and infrastructure teams are actively implementing measures to address the root causes and strengthen network resiliency to prevent recurrences in the future. Specifically, teams are monitoring recovery progress, refining safety checks for planned optical maintenance, and optimizing regional traffic routing mechanisms to safeguard against unexpected capacity constraints. Root Cause The disruption originated during scheduled fiber optic maintenance, which unexpectedly compromised network capacity between data centers within the us-west1 region. Automated rerouting mechanisms failed to properly redistribute traf