Service Copernicus The Climate Change Monitoring Service (C3S), implemented by ECMWF on behalf of the European Commission, has published its latest Monthly Climate Bulletin, confirming the ongoing series of exceptionally high global temperatures. October 2025 became the third warmest October on record worldwide.

The average global surface temperature in October 2025 reached 15.14 °C, which represents an increase of 0.70 °C above the average for the month, set in the reference period 1991–2020. Based on data for the first ten months, it is already virtually certain that 2025 will end up as the second or third warmest year on record.

Crossing the pre-industrial frontier

According to the monthly C3S report, October 2025 was up to 1.55°C above the estimated 1850–1900 average, which is used to define pre-industrial levels. This made it the first month when the threshold was 1.50°C exceeded since April 2025. Although October 2025 was 0.16°C cooler than the warmest October on record in 2023 and 0.11°C cooler than October 2024 (the second warmest), the overall trend remains concerning.

Samantha Burgess, Strategic Climate Lead at ECMWF, highlighted that we are now in the decade in which the 1.5°C limit will likely be exceeded, which highlights the accelerating pace of climate change and the urgent need for action.

An extremely important finding is that although 2025 may fall just a few hundredths of a degree short of the 1.5°C limit above the pre-industrial average, the average global temperature over the last three years (2023–2025) is likely to exceed this 1.5°C limitIf this happens, it will be the first time the 1.5°C limit has been exceeded for three consecutive years.

Contrasts in Europe and warm oceans

Within Europe, October brought significant temperature contrasts. The most pronounced above-average temperatures were recorded over Fennoscandia and the southern Iberian Peninsula, while southeastern Europe experienced below-average temperatures.

Outside the continent, the highest above-average temperatures were observed in polar regions, primarily over the central Arctic Ocean, northeastern Canada, and East Antarctica.

The global average sea surface temperature (excluding the polar regions) was the third warmest for the month, reaching 20.54 °C. The North Pacific continued to experience significantly above-average temperatures, with record high temperatures recorded in the western part of the basin. The European sector of the Arctic Ocean and the eastern Indian Ocean also recorded record high and significantly above-average temperatures.

Hydrological and ice anomalies

October was also characterized by significant wet anomalies in southeastern Europe. Southwest Europe experienced a wetter month than usual. Countries such as Bulgaria, Serbia, southern Romania, Bosnia and Herzegovina, Greece and the western coast of Turkey experienced cold storm conditions accompanied by snow and heavy rain. Flooding in eastern Bulgaria claimed four lives. Above-average rainfall was also recorded in Norway, Sweden, Denmark, Ireland and parts of southern France.

Conversely, drier conditions with lower precipitation were observed in the northwestern part of the Iberian Peninsula (where drought warnings were issued), northern Italy, northeastern Europe and Iceland.

Below-average sea ice extent continued to be recorded in the polar regions. Antarctic sea ice extent was the third lowest for October on record, at 17.5 million km², about 6 % below the 1991–2020 average. Arctic sea ice reached the eighth lowest extent, about 12 % below average. Ice concentrations were lowest in the central Arctic Ocean, which corresponds to an area of significantly above-average surface air temperatures.

These monthly updates, based on the C3S ERA5 dataset, provide important monitoring of the current state of the climate and its key variables.. JRi