World's oceans hit highest temperature on record as El Niño grows

On August 23, 2026, the average surface temperature of the world's oceans outside polar regions hit a record 21.1°C (70°F), according to data from the European Copernicus Climate Change Service. This edges past the previous record of 21.09°C set in March 2024 and is far above average for the time of year. The record is particularly notable because global ocean temperatures typically peak in March or April, not August. Scientists say the warmth is driven by human-caused climate change and the growing El Niño phenomenon, which is expected to strengthen until Christmas and could be the strongest in centuries. Warmer oceans can supercharge extreme weather, raise sea levels, and harm marine life. The data is based on sea temperatures 10 meters below the surface, using measurements from buoys, ships, and satellites. The western English Channel has seen almost continuous marine heatwave conditions for more than three years, peaking at 7°C above normal in July. The oceans absorb more than 90% of the excess heat trapped by greenhouse gas emissions.