Anomalies in sea surface temperature for 22 August 2026. Data source: ERA5. Credit: C3S/ECMWF.
On August 22, the world’s oceans broke a record: the average temperature around the planet hit nearly 70 degrees Fahrenheit, the hottest they’ve ever been since the European Union’s Copernicus Climate Change Service (C3S) began making records back in 1979.
According to C3S, the average temperature of the entire ocean was 69.98 degrees Fahrenheit which is about 20 degrees cooler than the average bath.
“As a climate scientist, this is not surprising to me at all,” Zachary Labe, a climate scientist at Climate Central, told Scientific American. “It’s consistent with decades of research showing how our climate is changing as the planet warms. And without reductions in the burning of fossil fuels, this warming will only continue.”
Until August 22, the highest temperature recorded in the 47 years since 1979 occurred in March of 2024, when it hit 69.96 degrees F. That’s just a fraction less than August’s record, but any increase at all is worrisome, given the current trajectory we’re on.
“This record is another clear signal of an ocean under growing stress,” said Samantha Burgess, strategic lead for climate at the European Center for Medium-Range Weather Forecasts (ECMWF), in a statement to the press. “El Niño is adding heat to the system, but it is doing so on top of decades of human-driven warming. As ocean temperatures continue to rise, the risks to marine ecosystems and coastal communities also increase. The consequences are already visible: the number of marine heatwave days globally has more than tripled since the early 1990s, putting increasing pressure on marine ecosystems and the communities that depend on them.”
It can be easy to think that warmer oceans aren’t all that bad if you’re not exactly in the loop about how our complicated climate system works. Warmer seas are better to play around in, after all, but the Earth’s climate systems are delicately balanced. The warmer the oceans get, the bigger the storms are. Sea level rise worsens, and all manner of sea life from coral reefs to migrating whales are affected. We humans are reliant on it too, from the economy to our infrastructure.
Sadly, researchers expect things to get hotter, especially with the record-breaking El Niño the world is bracing for. “This won’t be the last time we say this,” Labe said, “and unfortunately, it’s very possible we could break this record again in the coming months.”
