Global sea surface temperatures hit a record high as El Niño returns

Global sea surface temperatures hit a record high for the time of year on June 21, according to two separate European climate services. The daily global average edged above the previous peaks set in 2023 and 2024, coming as a new El Niño pattern takes hold in the Pacific. The Copernicus Climate Change Service, run by ECMWF, put the figure at about 69.5°F (20.8°C), while the Copernicus Marine Service operated by Mercator Ocean International reported close to 70°F (21.1°C). Both services used different methods, but their agreement signals a strong trend. NOAA issued an El Niño advisory on June 11, and the World Meteorological Organization urged governments to prepare earlier, with forecasts suggesting a chance of reaching the “very strong” tier. Warmer seas can intensify storms, raise sea levels, and stress marine ecosystems.