Oceans Hit Record 21°C in June: Global Sea Surface Temperature Peaked at 21°C on June 21, Beating 2023 and 2024 Records With El Niño Set to Push Further
The Guardian reports that global sea surface temperatures hit a record high of 21°C on June 21, surpassing previous June records of 20.83°C in 2023 and 20.86°C in 2024, according to the EU’s Copernicus Climate Change Service and Copernicus Marine Service, with June’s monthly average settling at 20.98°C.
Marine Heatwaves Affected 82% of the Global Ocean in the First Half of 2026, With the Mediterranean Breaking Its Own June Record at 24.3°C
The Mediterranean broke its June record at 24.3°C, surpassing previous highs set in 2023 and 2025, while marine heatwaves hit 98% of the Mediterranean basin during the first six months of the year. Marine heatwaves expanded steadily throughout the period, ultimately affecting around 82% of the global ocean, according to Copernicus lead oceanographer Simon van Gennip. The tropical Pacific also recorded its hottest June ever at 27.26°C.
Copernicus Director Warns El Niño’s Arrival on June 2 Could Drive 2026 Into the Warmest Year Ever Recorded, Compounding Long-Term Greenhouse Gas Warming
Carlo Buontempo, director of the Copernicus Climate Change Service, warned that “current conditions could indicate the beginning of a new phase, leading, once more, to uncharted territory,” adding that “with ocean temperatures at these levels and El Niño on the horizon, we are likely to see more temperature records fall in the coming months.” The oceans absorb roughly 90% of excess heat generated by greenhouse gas emissions, and warmer seas fuel tropical cyclones, destructive rainfall, sea level rise, and coral bleaching.
The ocean just broke its own June record for the third year in a row. Scientists say the next record is not a question of if, but when.
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