The world's oceans recorded their highest surface temperatures on record for July, partly due to the formation of an El Niño in the Pacific Ocean, according to the European climate monitoring service Copernicus.

The average ocean surface temperature outside the polar regions – between 60 degrees north and south latitude – was 20,96°C last month, surpassing the previous record of 20,89°C set in 2023. Last July was the second warmest on record globally, with temperatures exceeding pre-industrial levels by 1,47°C.

In Europe, sea surface temperatures reached record highs in July along the Atlantic coast and in the western Mediterranean, contributing to the spread of strong and extreme marine heatwaves. Abnormally high temperatures also persisted in the tropical Pacific Ocean, where El Niño continues to develop and is expected to intensify in the coming months.

Oceans absorb much of the excess heat from greenhouse gas emissions, so their warming leads to sea level rise due to thermal expansion of water, as well as longer and more intense marine heatwaves that damage coral reefs and marine ecosystems.