Marine heatwave Bulletin
Forecasts for 3 January 2026​

European Zone

North Atlantic

The intensity of the marine heatwaves in the Bay of Biscay, between Iceland and the British Isles remain as well as in the North Sea and Baltic Sea is stable, with moderate and strong categories. The extent of these marine heatwaves is decreasing. 

Global Ocean

Tropical Atlantic

The marine heatwaves in the Gulf of Mexico, the Caribbean Sea and as far as the centre of the basin are decreasing in intensity, with a decrease in the area affected by strong categories but still with moderate categories. The overall extent of these marine heatwaves is decreasing.

South Atlantic 

The marine heatwave around 30°S is intensifying, going from moderate category to mainly strong and locally severe categories. A tongue of moderate categories is developing from the coast of Namibia to the centre of the basin.

Tropical Pacific 

 The marine heatwaves around the Philippines, Indonesia and Papua New Guinea are intensifying with the development of strong categories. The extent of marine heatwaves in these areas is stable, except between Papua New Guinea and New Zealand, where it is decreasing.  The area of the marine heatwave at 150°W is decreasing, but its intensity remains stable and mostly in the moderate category. The marine heatwave along the coast of Chile is stable in extent and intensifying, with an increase in the area affected by strong categories and the development of areas in severe category.

South Pacific

The marine heatwave between 90°W and 120°W is intensifying with the development of strong and locally severe categories. The marine heatwave areas to the north-east and south of New Zealand are expanding, and their intensity is increasing with the development of strong categories. 

Southern Ocean

The intensity of the marine heatwave between 30°E and 120°E is decreasing from strong to moderate categories. Its extent remains stable.