August 2025 ranked as the third-hottest August on record worldwide, with extreme heat gripping much of Western Europe and Asia, according to data released today by the Copernicus Climate Change Service (C3S).
Global average surface temperatures last month were 1.29°C above pre-industrial levels (1850–1900), the agency reported. Only August 2023 and August 2024 were hotter. The announcement follows July’s figures, which also placed that month among the hottest ever documented.
Copernicus compiles its monthly reports using satellite data, ground observations, and advanced climate models, with records dating back more than eight decades. These datasets show a clear trajectory of intensifying global warming.
Across Europe, August’s heat was relentless. Spain endured a record 16-day heatwave, the longest in its history, which health officials estimate contributed to more than 1,100 excess deaths. Southwestern France also broke multiple temperature records on August 11, with Bordeaux, Bergerac, and Angouleme each surpassing 41°C.
The scorching conditions fueled wildfires across southwestern Europe, marking the third major heatwave of the summer. “With oceans still abnormally warm, these events highlight both the urgent need to cut emissions and the importance of adapting to escalating extremes,” said Samantha Burgess, deputy director of C3S.
Elsewhere, abnormal warmth was reported in northern Siberia, parts of Antarctica, China, the Korean Peninsula, Japan, and the Middle East. National agencies in Asia had already flagged late-summer extremes, with heat records tumbling from China to Japan.
Overall, the June-to-August period showed the sharpest warming in the northern hemisphere, particularly across Asia. The hottest month ever recorded remains July 2023, while Copernicus’ coldest record dates back to January 1940.
