Record global sea surface temperature reported as El Niño amplifies ocean heat
The Copernicus Climate Change Service has measured the highest daily average sea surface temperature ever recorded. The spike is attributed to the combined effects of ongoing climate warming and a strengthening El Niño pattern. Scientists warn that the ocean is facing exceptional stress from these conditions.
The record reading of 21.1°C was captured by satellite sensors on August 22, surpassing the previous mark of 21.09°C set during 2024's El Niño event. What makes this notable is the timing—daily ocean temperature peaks typically arrive in March or April following the Southern Hemisphere summer, not late August.
The current El Niño, declared underway on June 11, follows a pattern of recent months where both June and July posted record-high average sea surface temperatures. Scientists have flagged the possibility that this event could reach "super" status, exceeding the strength of the last El Niño, which itself contributed to 2024 becoming the hottest year on record.
Coastal communities and marine ecosystems could face mounting pressure as ocean temperatures climb. Warmer seas may accelerate coral bleaching, disrupt fisheries that millions depend on for food and income, and intensify storm systems that threaten coastal infrastructure. The combination of long-term warming with a potentially historic El Niño could push already-stressed systems past critical thresholds, affecting food security and