Global Sea Surface Temperatures Near Record Levels in April 2026

The service, part of the European Centre for Medium-Range Weather Forecasts (ECMWF), reported that near-record ocean temperatures were recorded as scientists warned of increasingly frequent climate extremes driven by persistent warming trends.

In its April update, C3S said that while El Niño conditions are expected to develop in the coming months, unusually high sea surface temperatures were observed across most regions outside the polar areas. Severe marine heatwave conditions were recorded across large parts of the tropical Pacific.

Global sea surface temperatures reached around 21°C last month, making it the second-highest April value on record. The highest April ocean temperature was recorded in 2024.

Extremely warm conditions were also observed across a broad area stretching from the central equatorial Pacific to the west coasts of the United States and Mexico, where “severe” marine heatwave conditions developed.

April 2026 was also recorded as the third-warmest April globally. The warmest April on record was in 2024, followed by 2025.

Land surface temperatures averaged 14.89°C last month, which is 0.52°C above the 1991–2020 April average.

In Europe, the average surface temperature stood at 8.88°C, making April 2026 the 10th warmest April on record for the continent.

C3S Deputy Director and Strategic Climate Lead Samantha Burgess said the data reinforced signals that global temperatures remain persistently high.

“Sea surface temperatures remained close to record levels, widespread marine heatwaves were observed, Arctic sea ice stayed well below average, and Europe experienced sharp contrasts in temperature and precipitation. All of these are hallmark features of a climate increasingly shaped by extremes,” she said.