Global temperatures remained near historic highs in 2025, making it the third hottest year ever recorded and extending a run of exceptional warmth that now spans more than a decade, according to data released Wednesday by European and US climate monitoring organisations.
Figures from the EU’s Copernicus Climate Change Service and the US-based Berkeley Earth show that the past 11 years are the warmest since modern records began. While 2024 remains the hottest year on record and 2023 ranks second, 2025 followed closely behind, only 0.01 °C cooler than 2023 and 0.13 °C cooler than 2024.
Taken together, the data reveal a striking milestone. Average global temperatures across the three-year period from 2023 to 2025 exceeded 1.5 °C above pre-industrial levels for the first time, Copernicus said. Although this does not mean the long-term Paris Agreement threshold has been formally crossed, it signals how close the climate system now is to that limit.
According to the ERA5 dataset, the global surface air temperature in 2025 averaged 1.47 °C above the 1850–1900 baseline, compared with 1.60 °C in 2024. Scientists estimate that long-term global warming currently stands at around 1.4 °C. At the present pace, Copernicus says the Paris Agreement’s 1.5 °C long-term limit could be reached by the end of this decade, far earlier than projections made when the agreement was signed.
The sustained heat of the past three years reflects a combination of long-term human-driven warming and shorter-term natural influences. Rising greenhouse gas concentrations remain the dominant factor, fuelled by continued emissions and a weakening ability of natural systems to absorb carbon dioxide. At the same time, ocean temperatures reached unusually high levels, boosted by El Niño conditions in 2023 and 2024 and other forms of ocean variability amplified by climate change.
In 2025, those ocean influences shifted. The equatorial Pacific spent much of the year in near-average or weak La Niña conditions, which tend to dampen global temperatures slightly. As a result, air and sea-surface temperatures in the tropics were lower than in the previous two years, though still well above average in many regions. Cooler tropical conditions were partly offset by pronounced warmth at higher latitudes.
Polar regions
Annual average temperatures reached record levels in the Antarctic in 2025 and the second-highest level on record in the Arctic. Several other regions also saw record warmth, including parts of the northeastern Atlantic, far eastern and north-western Europe, central Asia, and areas of the Pacific.
“This report confirms that Europe and the world are in the warmest decade on record and that the European Commission’s investment in Copernicus continues to be critical,” said Florian Pappenberger, Director-General of the European Centre for Medium-Range Weather Forecasts. “Preparedness and prevention remain possible but only when action is guided by robust, scientific evidence.”
The impacts of the heat were felt across land and sea. About half of the world’s land surface experienced more days than average with at least strong heat stress in 2025, defined as a “feels-like” temperature of 32 °C or higher. The World Health Organization identifies heat stress as the leading cause of weather-related deaths globally.
High temperatures also contributed to intense wildfire activity, particularly in dry and windy regions. Parts of Europe recorded their highest annual wildfire emissions, while large fires in North America released carbon and harmful air pollutants that degraded air quality over wide areas, according to the Copernicus Atmosphere Monitoring Service.
Extreme events formed the backdrop to the year, including record heatwaves, severe storms across several continents, and destructive wildfires in Spain, Canada, and southern California. While the Copernicus report does not analyse individual events, it places them within the wider pattern of a rapidly warming climate.
“The fact that the last eleven years were the warmest on record provides further evidence of the unmistakable trend towards a hotter climate,” said Carlo Buontempo, Director of the Copernicus Climate Change Service. “We are bound to pass it; the choice we now have is how to best manage the inevitable overshoot and its consequences on societies and natural systems.”
As greenhouse gas concentrations continue to rise, scientists say sustained monitoring will remain essential for understanding risks and guiding responses. “The atmosphere is sending us a message, and we must listen,” said Laurence Rouil, Director of the Copernicus Atmosphere Monitoring Service.
Article Source:
Press Release/Material by Copernicus Climate Change Service (C3S)
Featured image: Annual surface air temperature anomalies for the Arctic region (north of 40°N) for each year from 2002 to 2025, relative to the average for the 1991–2020 reference period. A non-linear colour scale is used to enhance the visibility of smaller anomalies and distinguish larger deviations. Data source: ERA5 Credit: C3S/ECMWF
