The Copernicus Climate Change Service (C3S) reported that the global daily average sea surface temperature for the extra-polar ocean (60°S–60°N) reached a record 21.104°C on August 22, 2026, just above the earlier record of 21.09°C from March 1, 2024. An August record is unusual since ocean temperatures usually peak in March–April; the previous August high was 20.98°C in 2023. A developing El Niño is adding heat to oceans already warmed by climate change. Warmer seas can cause sea-level rise, marine heatwaves, coral damage, stronger storms and lower CO₂ absorption.