2025 third hottest year on record: EU climate change service

The planet experienced its third-warmest year on record in 2025, and average temperatures have exceeded 1.5 degrees Celsius of global warming over three years, the longest period since records began, EU scientists have said.

The data from the European Union’s European Centre for Medium-Range Weather Forecasts (ECMWF) found on Wednesday that the last three years were the planet’s three hottest since records began, with 2025 marginally cooler than 2023, by just 0.01°C.

Britain’s national weather service, the UK Met Office, confirmed its own data ranked 2025 as the third-warmest in records going back to 1850. The World Meteorological Organization will publish its temperature figures later on Wednesday.

The hottest year on record was 2024.

Extreme weather events

ECMWF said the planet also just had its first three-year period in which the average global temperature was 1.5°C above the pre-industrial era, the limit beyond which scientists expect global warming will unleash severe impacts, some of them irreversible.

“1.5°C is not a cliff edge. However, we know that every fraction of a degree matters, particularly for worsening extreme weather events,” said Samantha Burgess, strategic lead for climate at ECMWF.

Governments pledged under the 2015 Paris Agreement to try to avoid exceeding 1.5°C of global warming, measured as a decades-long average temperature compared with the pre-industrial era.

But their failure to reduce greenhouse gas emissions means that level could now be breached before 2030 — a decade earlier than had been predicted when the Paris accord was signed in 2015, ECMWF said.