2025 was the third warmest year ever recorded, just below 2023 and 2024

Copernicus, the European Union's weather service, reported that 2025 was the third warmest year ever recorded, only slightly (by 0.01 °C) colder than 2023 and 0.13 °C colder than 2024, the warmest year ever recorded. The last 11 years have been the hottest ever recorded. The global temperatures of the last three years (2023-2025) have averaged more than 1.5 °C higher than the pre-industrial level (1850-1900). This is the first time that a three-year period has exceeded the 1.5 °C limit.

The air temperature over global land areas was the second warmest, with Antarctica recording the warmest annual temperature ever recorded and the Arctic the second warmest. In 2025, the global surface air temperature was 1.47 °C above the pre-industrial level, following 1.60 °C in 2024, the warmest year ever recorded.

Using different methods, the current long-term global warming level is estimated to be around 1.4 °C above the pre-industrial level. On the basis of the current warming rate, the 1.5 °C limit set by the Paris Agreement for long-term global warming could be reached by the end of this decade, more than a decade earlier than predicted on the basis of the warming rate when the agreement was signed.

The last three years, from 2023 to 2025, have been exceptionally warm for two main reasons.
The first is the accumulation of greenhouse gases in the atmosphere, due to continuous emissions and the reduction of carbon dioxide absorption by natural sinks.
The second is the reaching of exceptionally high levels of the sea surface temperature in all oceans, associated with the El Niño phenomenon and other factors of ocean variability, amplified by climate change.

Other factors include changes in the amount of aerosols and low clouds and changes in atmospheric circulation. Carlo Buontempo, Director of the Copernicus Climate Change Service, commented: 'The fact that the past eleven years have been the warmest on record provides further evidence of the unmistakable trend towards a warmer climate. The world is rapidly approaching the long-term temperature limit set by the Paris Agreement. We are destined to exceed it; the choice we now have is how best to manage the inevitable overshoot and its consequences for societies and natural systems'.