Earth’s average temperature last year hovered among the three hottest on record, and multiple international climate monitoring groups said the recent pattern points to a warming pace that may be increasing. The latest assessments came as the World Meteorological Organization and other research teams compared temperature records across 2023, 2024 and 2025, finding those years close enough to suggest they are effectively clustered near the same high level.
The World Meteorological Organization said Earth’s 2025 average temperature was 15.08 degrees Celsius (59.14 degrees Fahrenheit), which it calculated as 1.44 degrees Celsius (2.59 degrees Fahrenheit) warmer than pre-industrial times when averaging eight different data sets. The monitoring data used by many of the teams goes back to 1850. The groups said all three of the last years have hovered near the internationally agreed limit of 1.5 degrees Celsius warming since the mid-19th century.
Researchers also described small differences between methods and datasets that nonetheless converge on the same broad conclusion. Six science teams calculated that 2025 ranked behind 2024 and 2023, while two other groups — NASA and a joint American and British team — reported that 2025 was slightly warmer than 2023. The World Meteorological Organization, NASA and the National Oceanic and Atmospheric Administration said the gap between the two years was only about 0.02 degrees Celsius (0.04 degrees Fahrenheit), which they described as “pretty much a tie.”
When viewed across the three-year span, scientists said the trend is harder to reconcile with a steady, linear rise. NOAA climate monitoring chief Russ Vose said 2023, 2024 and 2025 “seemed to jump up,” and Robert Rohde, chief scientist at Berkeley Earth, said “The last three years are indicative of an acceleration in the warming.” Rohde said nearly all of the warming is driven by human-caused greenhouse gas emissions, while noting that the past three years may also have been boosted by factors including less soot pollution from ships, peak solar activity, and “perhaps a 2022 underwater volcano eruption,” according to the monitoring group’s reporting.
Copernicus climate service strategic lead Samantha Burgess said the “overwhelming culprit is clear: the burning of coal, oil and natural gas.” Burgess, speaking to The Associated Press, said, “Climate change is happening. It’s here. It’s impacting everyone all around the world and it’s our fault.” Copernicus and Japan use a combination of satellite data and computer simulations, while other teams rely on ground and sea observations, but the teams said their different approaches produced results that were within less than a tenth of a degree of each other.
The temperature assessments were released as scientists warned that higher heat puts people at increased risk and raises the likelihood of damaging extreme weather. Burgess said in a warmer world, extreme events become more frequent and more intense, pointing to 2025’s Los Angeles wildfires and saying that in severe storms or flooding events, the rain can be more intense. Copernicus reported that 2025 included numerous heat waves that broke local or national records, and it tied those extremes to impacts on people’s bodies.
Berkeley Earth calculated that 770 million people — about one out of every 12 people on the planet — experienced record annual heat in 2025, including 450 million in China, according to Copernicus reporting. The monitoring groups also highlighted additional record hot spots across parts of Australia, northern Africa, the Arabian peninsula and Antarctica, and they said the continental United States had its fourth warmest year on record, as determined by NOAA.
Scientists said natural variability still influences year-to-year temperature, even as the long-term warming continues. They cited the El Niño/La Niña oscillation, with warm El Niño events typically pushing temperatures up and cool La Niña phases tending to depress them. NOAA’s Vose said last year featured two weak, cool La Niñas, which meant “a big part of the surface of the Earth” was cooler than it otherwise would be, helping to “tuck a little temperature down” and limit the spike.
Looking ahead, some forecasts suggest an El Niño could develop during 2026 or soon after, though meteorologists described the outlook as uncertain. Carlo Buontempo, director of Copernicus’ climate service, said that when the next El Niño materializes — which he expects within the next couple of years — it will likely drive another record annual temperature. Several monitoring groups predicted 2026 would be about as hot as 2025, and they said Copernicus and Berkeley Earth both calculated that 2029 is the likely year when the planet’s long-term average will breach the 1.5-degree threshold.
Burgess said the consequences of that trajectory would show up in the frequency and cost of extreme events. She said, “In a decade’s time when we’re in the 2030s … the number of extreme events around the world will increase. The cost associated with the damages and impacts of those extreme events will be worse,” adding, “And we will look back to the mild climate of the mid 2020s with nostalgia.”