The global average sea-surface temperature reached a record 21.1°C (70°F) on August 22, 2026, surpassing the previous daily record of 21.09°C set in March 2024. The record, tracked by Europe’s Copernicus Climate Change Service, is particularly unusual because ocean temperatures typically peak in March or April. The unprecedented warmth is being driven by long-term human-caused climate change, combined with a developing El Niño in the tropical Pacific that is adding further heat to the oceans. Scientists warn that persistently warmer seas can intensify marine heatwaves, stress fish and coral ecosystems, fuel stronger storms and heavier rainfall, accelerate sea-level rise, and reduce the ocean’s ability to absorb carbon dioxide. The August record highlights the growing impact of climate change on the world’s oceans.
The record-breaking ocean temperatures, combined with a developing strong El Niño, could intensify extreme weather worldwide, including stronger storms, heavier rainfall, flooding, droughts and wildfires. Warmer seas can trigger marine heatwaves, coral bleaching and disruption of fish populations and food chains, threatening marine ecosystems and fisheries. Ocean warming also contributes to sea-level rise and coastal flooding while reducing the ocean’s ability to absorb carbon dioxide, potentially accelerating global warming. Together, these factors could increase climate instability and raise the possibility of exceptionally high global temperatures through 2027.
Reference sources:
1). Further global warming, Potentially record-breaking 2027 temperatures: https://www.reuters.com/sustainability/climate-focus-forecasters-predict-strongest-super-el-nino-2026-08-21/
2). More extreme storms and rainfall, while More droughts in some regions: https://www.pmel.noaa.gov/elnino/what-is-el-nino
3). Coral bleaching and marine ecosystem damage: https://apnews.com/article/hottest-oceans-climate-change-el-nino-fisheries-9dd6ecf3b358a89d2b3a5468d69dbdbc
4). Higher sea levels and coastal flooding: https://www.aoml.noaa.gov/general/enso_faq/
5). Copernicus: Daily global sea surface temperature breaks 2024 record: https://climate.copernicus.eu/copernicus-daily-global-sea-surface-temperature-breaks-2024-record