Ocean surface temperatures climbed to near-record levels in March, according to the EU’s Copernicus climate service, adding to concerns over rising global temperatures and a possible return of El Niño conditions.
The monthly climate bulletin, released on Friday, comes after three consecutive years of record global heat. Scientists warn that a likely return of El Niño later this year could further intensify warming.
Global sea surface temperatures reached 20.97°C in March, excluding polar regions, just 0.1°C below the record set in March 2024. According to Copernicus, the upward trend has continued into April.
El Niño, a natural climate pattern involving the periodic warming of ocean waters in parts of the Pacific, has a wide-ranging impact on global weather. The most recent event, spanning 2023 and 2024, contributed to those years becoming the hottest on record.
Copernicus said current ocean temperatures may indicate a shift towards El Niño conditions. The World Meteorological Organization has also assessed that a return is likely this year, as La Niña conditions weaken. In early March, it estimated a 40% probability of El Niño developing by July.
Europe and global trends
Nearly all of Europe, the fastest-warming continent, recorded above-average temperatures in March, particularly in northern Europe, the Baltic region and northwestern Russia.
The month was the second warmest March ever recorded in Europe, according to Copernicus data.
Globally, March ranked as the fourth warmest on record, with an average temperature of 13.94°C. This was 1.48°C above the estimated pre-industrial average for 1850 to 1900 and 0.53°C higher than the 1991 to 2020 average for the month.
Extreme heat patterns persisted elsewhere. In the western United States, temperatures exceeded 40°C and reached up to 44°C in some areas.
Carlo Buontempo, director of the Copernicus Climate Change Service, said the latest figures highlight growing strain on the climate system.
He said that while each indicator is striking on its own, together they point to a system under increasing and sustained pressure.