Cloud Outage Analysis
AWS Outage Cost - History, Real Losses & Your Exposure
Updated July 2026 · 10 major incidents documented
AWS Outage History, In Brief
AWS has had 10 major documented outages since 2012, and every one in this history struck the us-east-1 (Northern Virginia) region. The most recent was May 2026, a roughly 28-hour single-availability-zone (use1-az4) failure caused by a data-center cooling/thermal event that knocked EC2 and EBS offline and took Coinbase (about 7 hours), FanDuel, and CME Group down - the longest single stretch of AWS downtime in this record. The largest region-wide event was October 2025, a roughly 15-hour failure triggered by a DynamoDB DNS race condition that cascaded across EC2, Lambda, and STS and affected around 70,000 organizations. The two costliest were the December 2021 7-hour us-east-1 outage and the February 2017 S3 outage, each with aggregate customer losses estimated at $150M+. Significant AWS incidents have occurred at a rate of roughly 1-2 per year. Full chronology and SLA credit math below.
AWS Outage & Downtime Statistics
10
Major outages since 2012
~1-2/yr
Incident frequency (2017-2026)
10 / 10
In us-east-1 (region concentration)
~28h
Longest single event (May 2026)
$150M+
Costliest (Dec 2021, Feb 2017)
Frequency reflects the 10 major incidents documented in the chronology below, not every status-page event. Region concentration counts documented major outages, all of which struck us-east-1; AWS has had smaller incidents in other regions not listed here.
AWS Outage History
| Date | Region | Services | Duration | Impact | Est. Cost |
|---|---|---|---|---|---|
| May 2026 | us-east-1 (use1-az4) | EC2, EBS (cooling/thermal event); ELB, EKS, Redshift, MSK | ~28 hours | Single AZ; Coinbase ~7h, FanDuel, CME Group offline | $25M+ est. |
| Oct 2025 | us-east-1 | DynamoDB DNS, cascaded EC2/Lambda/STS | ~15 hours | ~70K orgs, 17M+ reports | $38-581M insured est. |
| Nov 2023 | us-east-1 | CloudFront, Route53 | ~4 hours | Global CDN degradation | $20M+ est. |
| Dec 2021 | us-east-1 | EC2, ECS, Lambda, SNS | ~7 hours | Major global disruption | $150M+ est. |
| Jun 2021 | us-east-1 | EC2, VPC networking | ~4 hours | Significant EC2 impact | $30M+ est. |
| Nov 2020 | us-east-1 | Kinesis (cascading) | ~13 hours | Cascaded to IAM, Cognito, CloudWatch | $50M+ est. |
| Aug 2019 | us-east-1 | EC2, ELB | ~8 hours | Multiple East Coast services | $25M+ est. |
| Mar 2019 | us-east-1 | EC2, VPC | ~4 hours | Network connectivity issues | $15M+ est. |
| Feb 2017 | us-east-1 | S3 | ~4 hours | Significant internet-wide disruption | $150M+ est. |
| Jun 2012 | us-east-1 | EC2, RDS, EBS | ~8 hours | Netflix, Instagram, Pinterest affected | $100M+ est. |
Cost estimates are aggregate customer losses except where noted. AWS does not disclose customer impact figures. The October 2025 figure is CyberCube's preliminary insured-loss range ($38M-$581M, clustering toward the lower end); other estimates are based on analyst reports and revenue-at-risk modeling. The May 2026 event was confined to a single Availability Zone (use1-az4) after a data-center cooling/thermal event; no firm analyst loss figure has been published, so its cost is a conservative revenue-at-risk estimate reflecting the multi-hour outages at Coinbase, FanDuel, and CME Group (per AWS's status updates and The Register). Updated July 2026.
AWS SLA Credit Rules
| Service | SLA % | Credit (99% to SLA) | Credit (<99%) | Claim Window |
|---|---|---|---|---|
| EC2 | 99.99% | 10% of monthly fee | 30% of monthly fee | 30 days |
| S3 Standard | 99.9% | 10% | 25% | 30 days |
| RDS Multi-AZ | 99.95% | 10% | 25% | 30 days |
| Lambda | 99.95% | 10% | 25% | 30 days |
Credits applied to future invoices. Business or Enterprise support required. Full SLA credit asymmetry analysis.