The planet just endured its third-hottest September on record, according to data released by the Copernicus Climate Change Service on Thursday, October 9. Despite not surpassing last year’s record heat, the month remained alarmingly close to historic highs as global temperatures continued to hover near unprecedented levels.
Copernicus reported that September 2025 was 1.47°C warmer than the 1850–1900 pre-industrial average — a period before human activity began significantly altering the climate.
“The global temperature context remains much the same, with persistently high land and sea surface temperatures reflecting the continuing influence of greenhouse gas accumulation in the atmosphere,” said Samantha Burgess, strategic lead for climate at Copernicus.
Scientists warn that even small temperature increases amplify the risk of climate extremes and push the planet closer to irreversible tipping points. The steady rise has been driven largely by human emissions from the widespread burning of fossil fuels since the Industrial Revolution.
This year’s persistent heat places 2025 on track to become one of the three hottest years ever recorded, following 2024 and 2023.
The findings come as global leaders prepare to meet in Brazil next month for the annual UN climate summit, where nations are under mounting pressure to accelerate emission cuts and curb the approval of new oil, coal, and gas projects.
Copernicus, which draws its data from billions of satellite, ship, and weather station measurements dating back to 1940, said this current warming phase is likely the most intense the Earth has seen in the last 125,000 years.
