The Copernicus Climate Change Service (C3S) has reported that October 2025 was the third-warmest October on record globally, with the year on course to rank among the three warmest years in the instrumental record.
According to C3S data derived from the ERA5 reanalysis dataset, the global average surface air temperature for October was 15.14°C, which is 0.70°C above the 1991–2020 average and 1.55°C above pre-industrial levels (1850–1900). Only 2023 and 2024 recorded warmer Octobers. The 12-month average from November 2024 to October 2025 stands 0.62°C above the 1991–2020 baseline and 1.50°C above pre-industrial levels.
Samantha Burgess, strategic lead for climate at Copernicus ECMWF, commented, “We are now in the decade where the 1.5°C limit is likely to be exceeded, highlighting the accelerating pace of climate change and the urgent need for action. October 2025 was the third-warmest October on record globally, and while 2025 may not be the hottest year, it is almost certain to rank in the top three. The last three years saw exceptional temperatures, and the average for 2023–2025 is likely to exceed 1.5°C, the first time for a three-year period.”
Regional and Ocean Conditions
Across Europe, the average October temperature was 10.19°C, around 0.6°C above the 1991–2020 average – outside the 10 warmest on record. The most pronounced above-average air temperatures were recorded in Fennoscandia and the southern Iberian Peninsula, while southeastern Europe saw below-average conditions.
Globally, above-average temperatures were observed over the Arctic, northeastern Canada and East Antarctica, while colder anomalies appeared across southern and eastern Russia, Mongolia and parts of northern China.
The average sea surface temperature (SST) for October between 60°S and 60°N was 20.54°C, the third-highest. SSTs remained well above average in much of the North Pacific and eastern Indian Ocean, while cooling in the central and eastern equatorial Pacific signalled a shift toward La Niña conditions.
In the Arctic, sea ice extent was 12% below average, ranking eighth lowest for the month, while Antarctic sea ice was 6% below average, the third lowest for October.
Precipitation patterns across Europe were mixed, with wetter-than-average conditions in the Balkans and parts of Scandinavia, and drier weather across the Iberian Peninsula, northern Italy and northeastern Europe.
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