Global oceans break June temperature record with fears they’re headed into ‘uncharted territory’
The planet’s oceans are at unprecedented temperatures for this time of year, breaking the June temperature record, according to new data, with alarming implications for global weather and marine life.
The Pacific Ocean at Windansea Beach on June 20 in San Diego, California. Global oceans are at record hot temperatures for this time of year. (Photo Credit: Kevin Carter/Getty Images via CNN Newsource)
(CNN) — The planet’s oceans are at unprecedented temperatures for this time of year, breaking the all-time June record, according to new data, with alarming implications for global weather and marine life.
On June 21, average global sea surface temperatures reached 69.5 degrees Fahrenheit (20.86 Celsius), edging above the June record last set in 2024, according to data from Europe’s Copernicus Climate Change Service, which combines measurements from satellites, ships and buoys.
The record was echoed in another data set. Data from the Copernicus Marine Service, implemented by the non-profit Mercator Ocean International, found sea temperatures hit 69.38 Fahrenheit (21 Celsius) on June 21, beating the previous record last set in 2024 by 0.18 degrees Fahrenheit.
The abnormal heat has been driven by the onset of El Niño, a natural climate pattern characterized by unusually warm waters along the equatorial tropical Pacific Ocean. El Niño has only just started but it may intensify into one of the strongest in decades.
Layered underneath that is the human-driven climate crisis, which is also driving up temperatures. For decades, oceans have acted as the planet’s main heat sink, absorbing 90% of the excess heat produced by humans burning fossil fuels.
☀️ Get your forecast in the CNN Weather app
“Rising sea surface temperatures are therefore not unexpected,” said Michael Meredith, an ocean scientist at the British Antarctic Survey. “But the pace of warming we are now seeing is alarming.”
It’s not yet clear whether this unprecedented June heat is temporary or a sign of things to come, but experts are expressing concern.
“Current conditions could indicate the beginning of a new phase, leading, once more, to uncharted territory,” said Carlo Buontempo, director of Copernicus Climate Change Service. “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.”
What happens in the oceans has huge implications for global weather patterns. Hotter oceans keep the air warmer, fueling heat waves; energize storms making them fiercer; and increase evaporation, boosting the chances of extreme rainfall and flooding.
Ocean heat can also lead to the mass bleaching of coral reefs, the death of other marine life and increased sea level rise.
The-CNN-Wire™ & © 2026 Cable News Network, Inc., a Warner Bros. Discovery Company. All rights reserved.
Report a Typo
