The year 2025 saw the third warmest September ever recorded on Earth, with high temperatures near the poles and in Eastern Europe, according to data released Thursday, October 9, by the European Copernicus Observatory. September, with an average temperature of 16.11°C, was 1.47°C above the pre-industrial period (1850-1900), before the climate warmed sustainably due to human activity. It thus ranks behind the record set in 2023 and the second-hottest September in 2024. The year 2025 also saw the third-hottest July and August on record.
“The global temperature pattern remains unchanged, with stubbornly high readings over land and sea surfaces, reflecting the continued influence of greenhouse gas accumulation in the atmosphere,” commented Samantha Burgess, Copernicus Climate Strategist. The highest temperatures, compared to measurements dating back to 1940, affected parts of Europe, the Nordic countries, and Eastern Europe, from the Baltics to the Balkans.
“Outside Europe, temperatures were most above average in Canada, parts of Greenland, far northwest Siberia and nearby coastal regions, and large areas of Antarctica,” Copernicus added. This European Union scientific program publishes monthly weather reports for the entire planet, based on analyses combining satellite measurements, ground-based observations, and climate models. The data, which cover the last 85 years, make it possible to measure the trend increase in temperatures on Earth month by month.
