Global sea surface temperature hits record 21.1C
AM730 · 2 SOURCESabout 1 hour ago2 MIN
Summary
Global average sea surface temperature reached a record 21.1C on August 22, according to the Copernicus Climate Change Service, edging above the previous 21.09C high recorded on three days in March 2024. A Copernicus bulletin cited by another report said the new record was logged on the past Saturday, again at 21.1C, making it the highest daily global sea surface temperature on record. Scientists say the record is being driven by long-term human-caused warming, with the strengthening El Nino pattern adding further heat on top. They also stress that the timing is unusual, because global ocean temperatures typically peak in March or April rather than August.
Key Points
- Copernicus data showed the average surface temperature across non-polar oceans reached 21.1C on August 22, above the previous 21.09C record from March 2024
- The estimate is calculated from water temperatures at 10 metres below the surface, using buoy, ship and satellite observations combined into a global analysis
- Researchers say the record’s timing matters because global ocean temperatures usually peak in March or April, near the end of the Southern Hemisphere summer.
- Since 2026, average sea surface temperatures between 60 degrees south and 60 degrees north have repeatedly been near or at record highs
- Scientists linked the warming to greenhouse gas emissions, noting oceans absorb more than 90% of excess heat and warmer seas can fuel storms, sea-level rise and coral damage.
Why It Matters
For Hong Kong readers, warmer seas can mean more moisture and energy for storms affecting coastal cities, while weaker sea-breeze cooling may worsen heat on land. Rising ocean temperatures also increase pressure on fisheries, marine habitats and low-lying shorelines, issues that matter to a densely populated coastal economy.