Overview
- Copernicus/ECMWF reports a 2025 global mean of 14.97°C, 0.59°C above the 1991–2020 average and just behind 2024 while nearly matching 2023.
- WMO’s consolidated datasets and separate analyses by NASA, NOAA, Berkeley Earth, and the UK Met Office concur on a top‑three ranking for 2025, with minor methodological differences placing it second or third.
- The 2023–2025 global average exceeds 1.5°C above 1850–1900 for the first time, with agencies warning the Paris limit could be reached as a long‑term average by the end of the decade and projecting 2026 to rank among the warmest years.
- Scientists attribute recent warmth primarily to accumulating greenhouse gases alongside exceptionally high sea‑surface temperatures linked to El Niño and other ocean variability.
- Observed effects in 2025 included more days with intense heat stress over roughly half of global land, Antarctica’s warmest annual temperature, reduced polar sea ice, and high fire emissions in parts of Europe and North America.