Copernicus records 21.1C ocean surface temperature outside polar regions on 4 August
Record ocean temperature data confirm the upward trend driven by accumulated heat plus emerging El Niño. Measurement timing and spatial extent indicate the signal is no longer confined to peak season. Operational monitoring systems remain human-dependent for validation and rapid interpretation.
Measurements from buoys, ships and satellites at 10 m depth produced the global estimate. The record occurred months before the typical March-April southern hemisphere peak and before El Niño maximum, indicating the baseline warming trend already exceeds prior seasonal maxima. Marine heatwave conditions in the western English Channel have persisted above 3C anomaly for over three years with a July peak of +7C.
Copernicus: March 2025 global SST exceeds 21.2C with 70% probability under current ENSO forecast.
Sources (2)
- [1]Copernicus Climate Change Service SST product(https://climate.copernicus.eu/climate-data-store)
- [2]National Oceanography Centre analysis(https://noc.ac.uk/news/ocean-temperature-records-2024)