The world’s oceans reached their highest recorded daily global average sea-surface temperature on Aug. 22, 2024 [1].
This milestone signals an accelerating trend in marine warming that threatens global fisheries and disrupts weather patterns across the planet.
The European Copernicus Climate Change Service said the record was set Monday [1]. The daily global average sea-surface temperature hit 21.1°C [1]. This figure surpasses the previous record of 21.09°C, which was set in March 2024 [3].
Scientists attribute the surge to a combination of ongoing climate-change-driven warming and a strengthening El Niño in the Pacific [1, 2]. The warming trend has been persistent throughout the year. For example, the global average sea-surface temperature for June 2024 was 20.98°C [4].
"The record is another clear signal of an ocean under growing stress," Dr. Samantha Burgess said [2].
The Copernicus Climate Change Service said the oceans have reached their hottest temperature on record [1]. The service monitors these shifts to track how heat absorption in the water affects the atmosphere.
Rising ocean temperatures can lead to more intense storms, and the bleaching of coral reefs. Because the oceans absorb the vast majority of excess heat from greenhouse gas emissions, these records serve as a primary indicator of the planet's overall thermal imbalance [1, 2].
“The record is another clear signal of an ocean under growing stress.”
The breach of the 21.1°C threshold demonstrates that natural cycles like El Niño are compounding with human-induced climate change to push marine ecosystems toward critical tipping points. As the ocean absorbs more heat, it reduces its capacity to regulate global temperatures, likely leading to more volatile weather patterns and increased risks to biodiversity in the world's oceans.
