First four months of 2025 were warmest on record, says Copernicus

The first four months of 2025 were the warmest on record, according to the latest climate bulletin from the Copernicus Climate Change Service (C3S). Global surface air temperatures remained persistently high, with April 2025 ranking as the second-warmest April ever recorded.

The average surface air temperature last month reached 14.96 degrees Celsius, which was 0.60°C above the 1991-2020 average for April. While slightly cooler than April 2024 — the hottest on record — it was 1.51°C above the estimated pre-industrial average (1850-1900), keeping global temperatures over the critical 1.5°C threshold for the 21st time in 22 months.

The 12-month period from May 2024 to April 2025 was also exceptionally warm, averaging 1.58°C above pre-industrial levels.

“Globally, April 2025 was the second-hottest April on record, continuing the long sequence of months over 1.5ºC above pre-industrial,” Samantha Burgess, strategic lead for climate at the European Centre for Medium-Range Weather Forecasts (ECMWF), which implements the C3S, said in a presser. She called for continued climate monitoring as “essential tool for understanding and responding to the ongoing changes of our climate system.”

Across Europe, temperatures in April averaged 9.38°C — 1.01°C higher than the 1991-2020 average — making it the sixth-warmest April for the continent. Eastern Europe, western Russia, Kazakhstan and Norway experienced the most pronounced warm anomalies. In contrast, parts of Türkiye, Bulgaria, Romania, and northern Fennoscandia saw cooler-than-average temperatures.

Beyond Europe, temperatures soared above average across the Russian Far East, west-central Asia, much of North America, and parts of Australia and Antarctica. Colder-than-average conditions were observed in southern South America, eastern Canada, northern Australia, and eastern Antarctica.

Sea surface temperatures (SST) also remained strikingly high. April’s global SST averaged 20.89°C, the second-highest on record for the month and only slightly below the 2024 record. The northeast North Atlantic continued to show record-breaking warmth, while the Mediterranean Sea remained well above average.

Sea ice extent continued to dwindle. Arctic sea ice was 3 per cent below average—the sixth-lowest April extent in the 47-year satellite record. Antarctic sea ice was 10 per cent below average, with regional anomalies varying around the continent.

April’s hydrological extremes were equally notable. Much of central and eastern Europe, Great Britain, and southern Fennoscandia experienced drier-than-average conditions. Meanwhile, southern Europe, northern Norway, and western Russia saw wetter weather, with the Alpine region hit by floods, landslides, and avalanches due to heavy precipitation.

Elsewhere, severe rainfall in parts of Canada, Alaska, southern Africa, and northern Australia caused flooding and damage. At the same time, dry conditions prevailed across western North America, central Asia, southern Australia, and parts of South America.