The world’s oceans reached their highest recorded surface temperature Saturday, averaging 70 degrees Fahrenheit outside the polar regions, according to data from the European Union’s Copernicus Climate Change Service in a report by The Guardian. 

The record comes as a rapidly developing El Niño adds heat to decades of human-driven warming. Ocean temperatures typically peak in March and April, making an August record particularly notable.

More than 90% of heat trapped by carbon dioxide from fossil fuel burning enters the oceans. Scientists said warmer seas contribute to rising sea levels, intensify storms and rainfall, and drive marine heatwaves that threaten sea life and coastal livelihoods.

Dr. Samantha Burgess of Copernicus said the number of marine heatwave days worldwide has more than tripled since the early 1990s.

Hotter oceans also absorb carbon dioxide less efficiently, potentially weakening a major natural buffer against global warming. Copernicus’ ocean temperature records date to 1979, when high-quality satellite data became available.

Read more at The Guardian.