The Last 11 Years Were the Hottest Ever Recorded

The Earth’s climate is more out of balance than at any time in recorded history, according to the World Meteorological Organization (WMO). Its State of the Global Climate 2025 report confirms that the years 2015–2025 were the hottest 11‑year stretch ever observed, with 2025 ranking as the second or third hottest year on record.

“Humanity has just endured the eleven hottest years on record. When history repeats itself eleven times, it is no longer a coincidence. It is a call to act,” said UN Secretary‑General António Guterres.

More than 91% of excess heat is being absorbed by the oceans, which reached record warmth in 2025. Sea ice in both the Arctic and Antarctic shrank to near‑record lows, while glaciers from Iceland to North America suffered exceptional mass loss. Rising seas, driven by warming oceans and melting ice, are expected to continue for centuries.

Behind every weather forecast is a worldwide system of satellites, sensors and scientists keeping track of changes in real time. That same system provides the data for the State of the Global Climate report, which was released on World Meteorological Day, observed every year on March 23.

This year’s theme, “Observing Today, Protecting Tomorrow”, points to the idea that weather observation is not just about telling us if it will rain tomorrow. It is also about building early warning systems that protect lives and help communities prepare for the future.

WMO Secretary-General Celeste Saulo put it simply: “When we observe today, we don’t just predict the weather; we protect tomorrow. Tomorrow’s people. Tomorrow’s planet.”