Overview
- Copernicus services reported that global sea-surface temperatures in June 2026 set new records, with the monthly average reaching about 20.98°C and daily values exceeding prior highs.
- Scientists say the record June warmth reflects a developing El Niño interacting with an ongoing anthropogenic warming trend, which raises the probability that 2026 will rank among the hottest years on record.
- Widespread marine heatwaves have affected an estimated 82% of the ocean this year, with especially intense hotspots in the tropical Pacific and the Mediterranean and notable anomalies in temperate zones such as the English Channel.
- The heat is already harming life at sea, producing coral bleaching in French Polynesia, declines in plankton and stress on fish populations that could lead to local losses such as cod in parts of the Atlantic.
- Researchers are maintaining close monitoring to determine whether high sea temperatures will persist, warning that prolonged warming would erode the ocean’s ability to absorb heat and carbon and amplify extreme weather, storm intensity and sea-level rise.