2025 was one of the three hottest years on record, scientists find

Several national and international climate agencies report that 2025 ranked as the second- or third-warmest year on record, with the last three years the warmest on record and greenhouse gas concentrations rising.

Several U.S. and international climate agencies released analyses of global temperatures for 2025. NOAA, the EU's Copernicus service and the U.K. Met Office reported that 2025 ranked third-warmest on record, while NASA ranked it second and said it was effectively tied with 2023. The last three years now stand as the warmest in the instrumental record. Agencies connected the temperature rise to human-caused greenhouse gas emissions. What the agencies reported: - NOAA, Copernicus and the U.K. Met Office found 2025 to be the third-hottest year on record. - NASA found 2025 to be the second-hottest year and noted it was effectively tied with 2023. - The last three years are the warmest on record, with 2024 recorded as the warmest. - Copernicus reported that atmospheric greenhouse gas concentrations increased during 2025. - Copernicus also reported the lowest February global sea ice extent since satellite records began and that January 2025 was the warmest January on record. Summary: The assessments reinforce a continuing pattern of above-average global temperatures that agencies link to greenhouse gas emissions, and they note related signals such as low sea ice and record-warm months. The reports describe ongoing changes that are associated with sea level rise and increases in extreme weather. Undetermined at this time.