Global Sea Surface Temperatures Shatter Records Amid Intensifying El Nino

A man carries a child through sargassum seaweed after cooling off in the ocean in Miami Beach, Florida, June 11, 2026 [Rebecca Blackwell/AP]. The average global sea surface temperature has reached its highest level on record, according to a European Union agency, which warned that a rapidly intensifying El Nino and human-caused climate change are placing unprecedented strain on the world's oceans.

In a statement on Monday, the EU's Copernicus Climate Change Service reported that sea surface temperatures hit 21.1 degrees Celsius (69.98 degrees Fahrenheit) on Friday and Saturday, surpassing the previous record of 21.09C (69.96F) set in March 2024.

“This record is another clear signal of an ocean under growing stress,” said Samantha Burgess, the strategic lead for climate at the European Centre for Medium-Range Weather Forecasts (ECMWF). “El Nino is adding heat to the system, but it is doing so on top of decades of human-driven warming.”

Copernicus noted that the timing of this new record is particularly notable, as global ocean temperatures typically peak in March and April when the summer in the Southern Hemisphere draws to a close. However, this year's record was set in August.

Burgess told The Associated Press that oceans will continue to heat up until the current El Nino reaches its expected peak between November and January. The World Meteorological Organization also expects El Nino to strengthen in the coming months, while Copernicus indicated the event could reach levels unseen for several decades.

This added heat arrives as long-term fossil-fuel-driven warming has already raised ocean temperatures by 0.8C (1.44F), Burgess noted. Copernicus warned that these rising temperatures carry far-reaching consequences for marine ecosystems and coastal communities.

Warmer oceans contribute to sea-level rise through thermal expansion and increase the intensity of marine heatwaves, which damage coral reefs and seagrass beds. This disruption threatens food chains, fishing, and aquaculture industries, while also reducing the ocean's ability to absorb carbon dioxide and weakening a key defense against climate change.

Jane Lubchenco, an oceanographer and former head of the US National Oceanic and Atmospheric Administration, described the finding as very troubling. “An ocean this warm destabilises weather patterns and threatens food security, economic prosperity and marine life,” Lubchenco told the AP. “A warmer ocean is not our friend.”