WMO Reports Record Ocean Heat and the Highest Earth Energy Imbalance in 65 Years of Records

The WMO, the UN agency for weather and climate, published its State of the Global Climate 2025 report in March 2026. The report finds that 2025 was 1.43°C, plus or minus 0.13°C, above the 1850 to 1900 average, making it the second or third warmest year on record depending on the dataset. The 11 years from 2015 to 2025 were the 11 warmest in the observational record. The WMO combines several international temperature datasets, which is why its estimate differs slightly from the 1.47°C reported by the Copernicus Climate Change Service in January.

The report finds that ocean heat content reached a new record high in 2025. The WMO also reports that the Earth's energy imbalance, the difference between incoming energy from the sun and outgoing energy to space, reached its highest level in the 65-year observational record. Arctic sea ice extent averaged 10.10 million square kilometres in 2025, and Antarctic sea ice averaged 10.81 million square kilometres, according to the report. Sea level rise, driven by ocean warming and melting ice, poses long-term risks to coastal energy infrastructure, including ports, refineries, LNG terminals and power stations.

The report reviews extreme events that affected people and economies during the year. The report discusses the Paris Agreement goal of limiting warming to 1.5°C. The WMO notes that individual years above 1.5°C do not mean the long-term goal has been missed, because the goal refers to warming averaged over about two decades. Utilities, insurers and investors increasingly use climate scenarios to assess physical risks to assets. The WMO has also been leading the UN's Early Warnings for All initiative, which aims to ensure everyone on earth is covered by early warning systems for hazardous weather. The report draws on national meteorological services, satellite agencies and research institutions. The WMO's annual-to-decadal forecasts, published in late spring, provide probabilities for temperatures over the next five years.