Global ocean surface temperatures reached an unprecedented record high on June 21, 2026, according to European Union scientists, intensifying concerns over severe summer heatwaves and accelerating climate change across the planet.
Data released independently by the Copernicus Climate Change Service and the Copernicus Marine Service confirmed that average sea surface temperatures outside polar regions reached 20.86 degrees Celsius and 21 degrees Celsius respectively.
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These figures surpassed previous June records set during the 2023 and 2024 El Niño cycles, with current averages significantly higher than the pre-industrial average of 19.6 degrees Celsius recorded in 1870.
The rapid escalation of sea temperatures has been heavily influenced by the emergence of a tropical Pacific El Niño climate pattern alongside long-term human-driven greenhouse gas emissions.
Oceans act as Earth's primary heat sink, absorbing over 90 percent of the excess energy trapped by fossil fuel combustion.
In 2025, this thermal energy absorption reached an intensity equivalent to 12 Hiroshima-scale nuclear detonations per second.
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"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," said Carlo Buontempo, Director of the Copernicus Climate Change Service.
Buontempo noted that the world might be moving toward a highly volatile atmospheric state due to compounding climate factors, potentially leading to "uncharted territory."
Academic experts emphasized that the unprecedented trajectory aligns perfectly with established multi-decadal scientific projections regarding uncontrolled industrial carbon output.
