Global science and weather agencies found that 2025 was either the second- or third-hottest year recorded, according to eight different datasets consolidated by the World Meteorological Organisation (WMO).
The global average temperature in 2025 was 1.44°C above pre-industrial levels, with a margin of uncertainty of 0.13°C either higher or lower, according to the synthesis of eight datasets. Of the eight datasets consolidated, two found that 2025 was the second-warmest year in the 176-year record, and the remaining six ranked it as the third-hottest year recorded, the WMO said.
The Paris climate agreement seeks to limit the global rise in temperature to below 2°C above the pre-industrial average, and pursues a 1.5°C threshold.
The past three years, over 2023-25, are the three hottest years in all eight datasets, the WMO found. The average temperature across 2023-25 was 1.48°C above pre-industrial levels — again with a margin of uncertainty of 0.13°C — the consolidated data show.
The average global temperature in 2025 was 15.08°C based on the datasets, but the margin of uncertainty for this is much higher, at around 0.5°C, the WMO said.
"The year 2025 started and ended with a cooling La Nina and yet it was still one of the warmest years on record globally because of the accumulation of heat-trapping greenhouse gases in our atmosphere. High land and ocean temperatures helped fuel extreme weather", WMO secretary-general Celeste Saulo said.
The La Nina weather pattern typically leads to lower global temperatures, while the El Nino pattern has the opposite effect. These are naturally-occurring. But "the long-term increase in global annual average temperature is driven by the human-induced rise in the concentration of greenhouse gases in the atmosphere", UK Met Office climate scientist Colin Morice said.
The WMO collates data from the EU's Copernicus, Japan's Meteorological Agency, the UK's Met Office, the US' National Aeronautics and Space Administration and National Oceanic and Atmospheric Administration, and US non-profit Berkeley Earth. It has also this year used a UK-US dataset, DCENT, and China's Merged Surface Temperature dataset.
Science and weather agencies agree that 2024 is the hottest year on record.
