ACC News Brief
Climate Data Global
VERIFIED OBSERVATION - NOAA and ERA5 use different methods and reference periods
NOAA and Copernicus rank August 2026 as the warmest August on record
What happened
NOAA ranked August 2026 as the warmest August in its 1850-2026 record, at 1.32 degrees C above the 20th-century average and 0.08 degrees C above the previous tied records from 2023 and 2024. Copernicus, using ERA5, likewise ranked it the warmest August and statistically on par with July 2023 as the joint-warmest calendar month. NOAA also reported a record-high global ocean temperature for August.
ACC context
A single month more than 1.5 degrees C above an estimated preindustrial level does not by itself mean the Paris Agreement's long-term temperature threshold has been crossed. Neither monthly bulletin is an event-attribution study.
Why it matters
Two major climate-monitoring systems reached the same monthly ranking even though they use different methods and reference periods. The result extends the recent run of exceptional global heat across land and ocean.
What to watch
- Whether record ocean warmth persists as the strong El Nino evolves.
- NOAA's outlook that 2026 is very likely to finish among the five warmest years.
- Dataset updates and uncertainty ranges rather than treating small product differences as contradictions.
Sources & evidence
- Monitoring Global Temperature and Precipitation in August 2026NOAA NCEI monthly assessment published September 10, 2026, covering August 2026 and the June-August season.
- Copernicus: August was world's joint-hottest month on recordCopernicus Climate Change Service ERA5 monthly summary published September 10, 2026.
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