The World Meteorological Organization (WMO) on Wednesday confirmed that 2025 was one of the three warmest years on record, with a global average surface temperature at 1.44°C above the 1850-1900 average.
Ocean warming continues unabated, and the past 11 years are the warmest on record, reaffirming the ongoing climate crisis despite temporary La Niña cooling.
“The year 2025 started and ended with a cooling La Niña 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,” said WMO Secretary-General Celeste Saulo.
She noted that high land and ocean temperatures helped fuel extreme weather, heatwaves, heavy rainfall and intense tropical cyclones, underlining the vital need for early warning systems.
The past 11 years, from 2015 to 2025, have been the warmest on record. The three-year average from 2023 to 2025 holds the highest temperatures ever recorded, at 1.48°C above the pre-industrial era. This sustained warming reflects the ongoing global climate crisis.
WMO’s announcement coincided with data releases from several leading climate monitoring agencies, including the European Center for Medium Range Weather Forecasts Copernicus Climate Change Service (ERA5), NASA’s GISTEMP, Japan Meteorological Agency, and others.
This year, WMO incorporated two new datasets, the Dynamically Consistent ENsemble of Temperature (DCENT) and China Merged Surface Temperature Dataset (CMST), enhancing the robustness of its global temperature assessments.
While six of the datasets ranked 2025 as the third warmest year on record, two ranked it second warmest, showing minor variation based on differing methodologies.
The estimated actual global average temperature in 2025 was 15.08°C, with a larger margin of uncertainty due to data variability.
Ocean temperatures also reached record levels. A separate study published in Advances in Atmospheric Sciences revealed that ocean heat content in the upper 2000 meters increased by approximately 23 ± 8 Zettajoules from 2024 to 2025, an amount roughly 200 times the world’s total electricity generation in 2024.
About 90 percent of excess heat from global warming is absorbed by the oceans, making ocean warming a critical climate indicator.
Regionally, around 33 percent of the global ocean area experienced its top three warmest conditions historically, while 57 percent fell within the top five warmest, affecting the tropical and South Atlantic Oceans, Mediterranean Sea, North Indian Ocean, and Southern Oceans.
Despite the cooling influence of La Niña in 2025, the global annual mean sea surface temperature was 0.49°C above the 1981–2010 baseline, ranking it the third warmest year for ocean surface temperatures.
WMO emphasized that the consolidated authoritative analysis it provides is crucial for informed decision-making on climate action worldwide.
“WMO’s state of the climate monitoring, based on collaborative and scientifically rigorous global data collection, is more important than ever before because we need to ensure that Earth information is authoritative, accessible and actionable for all,” said Celeste Saulo.
The full report, State of the Global Climate 2025, will be released in March 2026, offering detailed data on greenhouse gases, surface and ocean temperatures, sea level rise, glacier retreat, and sea ice extent, alongside summaries of high-impact weather events.
As a specialized UN agency, WMO coordinates international cooperation in atmospheric science and meteorology to support climate monitoring, forecasting, and disaster mitigation.
Its ongoing work provides vital insights into the accelerating climate crisis, reaffirming the urgent need for global action.
