World’s oceans record hottest June, EU reports sustained warmth in early 2026

European Union climate monitors reported that the first half of 2026 experienced “sustained and exceptional ocean warmth,” marking the most prolonged period of elevated sea temperatures on record for the region. Data collected by the Copernicus Marine Service and national meteorological agencies showed average surface temperatures across the Atlantic and Mediterranean exceeding long‑term norms by up to 1.5 °C, with several hotspots persisting for weeks without the typical cooling cycles observed in previous years.

The unprecedented warmth has been linked to a combination of a strong El Niño event, reduced Arctic sea‑ice extent, and a persistent high‑pressure ridge over Western Europe, which together limited heat exchange between the ocean and atmosphere. Scientists warn that the anomaly could intensify marine heatwaves, disrupt fisheries, and increase the risk of coral bleaching in the Mediterranean, while also contributing to higher coastal evaporation rates and altered weather patterns inland. EU officials emphasized that the findings underscore the urgency of implementing adaptation measures and strengthening climate‑resilience strategies across member states.