Marine heatwave Bulletin
Forecasts for 7 March 2026 ​

Key takeaways

Mediterranean Sea –the marine heatwave in the western side of the basin is increasing.

North Pacific – the marine heatwave east of the Philippines extending to the centre of the basin is increasing in intensity but remains stable in extent.

Southern Ocean – increasing intensities in the marine heatwave between 60°E and 120°E. 

 

Waves

Marine heatwave categories

European zone

Mediterranean Sea

The marine heatwave in the western basin is increasing in intensity, with the area classified as severe expanding from Sicily to the French coast. The marine heatwave in the eastern basin, classified as moderate to severe, remains stable overall. 

North Atlantic

Marine heatwaves between Iceland and the British Isles, as well as in the English Channel and the Bay of Biscay, remain generally stable, with moderate and strong categories still in place.

Global Ocean

North Atlantic

In the Gulf of Mexico and the Caribbean Sea, only a few scattered areas remain in the moderate category. The marine heatwave extending from the Antilles to the centre of the basin is decreasing in size and remains generally in the moderate category. 

South Atlantic

The marine heatwave off the coast of Namibia is decreasing in size and intensity, with only a few scattered areas remaining in the moderate category. In the center of the basin around 15°S, the marine heatwave consisting of scattered areas in the moderate and strong categories remains generally stable. 

North Pacific

The marine heatwave in the center of the basin around 180°W and 50°N remains stable in intensity, with mostly moderate categories and locally strong to extremes categories, but is decreasing in area. The marine heatwave east of the Philippines extending to the centre of the basin is increasing in intensity, with the area of strong categories increasing, but remains stable in terms of surface area. The marine heatwave west of the North American coast remains stable in terms of surface area and intensity, with moderate categories still prevailing overall. 

South Pacific

The marine heatwave stretching from eastern Papua New Guinea to northern New Zealand is decreasing in intensity and size and has been downgraded to moderate category. The marine heatwave in the center of the basin is increasing in size and intensity and has been categorized as moderate to strong. The marine heatwave off the west coast of South America is decreasing in size but remains stable in intensity, with mostly moderate and locally strong categories 

Southern Ocean

The marine heatwave present between 60°E and 120°E increases in intensity, the surface area of strong categories increasing. 

Weekly temperature anomalies

Week of the 1 to 7 March 2026

Mediterranean Sea 0 °C to 2°C 
North Atlantic -3< °C to 3°C 
South Atlantic -3°C to >3°C1 
North Pacific -3°C to >3°C 
South Pacific -1°C to 3°C  
Southern Ocean -0.5°C to 1.5°C 

Forecasts for 7 March 2026

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NOTES

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