June Ocean Temperature Records Hit New Highs Amid El Niño

In June, ocean surface temperatures reached unprecedented levels. The Copernicus Marine Service recorded a global mean of 20.86 °C on 21 June, surpassing the previous record of 20.83 °C set in 2023‑24. Some independent measurements reported values around 21 °C.

Regional anomalies were substantial, with the Mediterranean, Baltic Sea, parts of the Pacific and northern Canada’s coasts experiencing temperatures up to six degrees above long‑term averages. The extreme warmth is linked to the strengthening El Niño, which adds additional heat to the ocean and prolongs atmospheric warming.

Scientists warn that such marine heatwaves can intensify land‑based heatwaves, fuel stronger storms, raise sea‑level rise, accelerate ice melt and stress marine ecosystems, including coral bleaching and disrupted fish populations.