Earth’s global surface temperature in 2025 was slightly warmer than in 2023, but within the margin of uncertainty the two years are effectively tied, according to an analysis by NASA scientists. Despite the continued warming trend, 2024 remains the hottest year on record since modern measurements began in 1880.
NASA said global temperatures in 2025 were lower than those recorded in 2024, averaging 2.14 degrees Fahrenheit (1.19 degrees Celsius) above the 1951–1980 baseline. The findings were produced by NASA’s Goddard Institute for Space Studies (GISS), which compiles surface air temperature data from more than 25,000 meteorological stations worldwide, along with sea surface temperature measurements from ships and buoys and observations from Antarctic research stations.
NASA’s analysis applies statistical methods designed to account for changes in the global distribution of temperature stations over time, as well as potential urban heat effects that could otherwise skew long-term trends.
Independent assessments from the U.S. National Oceanic and Atmospheric Administration, Berkeley Earth, the UK Met Office’s Hadley Centre, and Europe’s Copernicus Climate Change Service have reached similar conclusions. While these organisations use many of the same underlying datasets, their analyses rely on different methodologies and models. All concluded that 2025 ranked as the third warmest year on record, reinforcing evidence of a sustained long-term warming trend.
NASA said its full global surface temperature dataset, along with detailed information on the analytical methods used, is publicly available online, supporting transparency and ongoing climate research.
