World's oceans hit record heat in June 2025, with El Niño set to intensify warming

Global ocean temperatures in June 2025 reached their hottest levels on record for that month. More than 90% of the heat trapped by the greenhouse effect is absorbed by the oceans, with major knock-on effects for the planet's climate. Scientists warn that an approaching El Niño could heat ocean waters even further, intensifying extreme weather events on land.