North Atlantic (Europe region): The marine heatwave around the British Isles is increasing in intensity between Ireland and Iceland, with an increase in the strong category.
Tropical Atlantic: The marine heatwave in the Gulf of Mexico is intensifying and is now mostly in strong to severe category, with extreme category locally.
Indian Ocean: The marine heatwave around 0°S is decreasing in intensity, mostly in moderate category.
The marine heatwave off the coast of Portugal to Brittany is decreasing in size and intensity, with only a few areas remaining in the moderate category. The marine heatwave around the British Isles is increasing in intensity between Ireland and Iceland, with an increase in the strong category.
The marine heatwave in the western basin is decreasing in intensity and extent, with only a few moderate areas remaining. The marine heatwave in the eastern basin remains globally stable, with moderate and strong categories still present.
The marine heatwave south of Cuba is decreasing in size but remains in moderate to severe category. The marine heatwave in the Gulf of Mexico is intensifying and is now mostly in strong to severe category, with extreme category locally. The marine heatwave in the center of the basin around 60°W is decreasing in intensity and is now mostly in moderate category, with strong category locally.
The marine heatwave in the center of the basin between 30°N and 60°N is decreasing in intensity with the disappearance of severe and extreme categories and the decrease of strong categories towards 180°W; but it is increasing in intensity with the increase of strong categories and the appearance of severe categories towards 140°W.
The marine heatwave in the Sea of Okhotsk is decreasing in intensity and in extent, and is now mostly in moderate category, with strong category locally.
The marine heatwave in the Yellow Sea is increasing in intensity with strong, severe, and extreme categories.
The marine heatwave around 0°S is decreasing in intensity and is now mostly in moderate category, with strong category locally.
Mean sea surface temperature for the week 24 – 30 August 2025
| North Atlantic | -3°C to 2°C |
| Tropical Atlantic | -1°C to 2°C |
| Mediterranean Sea | 0°C to 1°C |
| North Pacific | -1°C to >3°C |
| Indian | -1°C à 2°C |
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Datasets and products: Global Ocean Physics Analysis and Forecast (sea surface temperature) E.U. Copernicus Marine Service/ Mercator Ocean International. https://doi.org/10.48670/moi-00016
