Marine heatwave Bulletin
Forecasts for 28 March 2026​

Key takeaways

  • Mediterranean Sea – marine heatwave is decreasing in intensity and extent.
  • North Pacific – active marine heatwaves in the north, central of the basin and off the west coast of the United States (California) increasing in intensity.
  • Southern Ocean – stable conditions of the marine heatwave at strong and severe categories.

 

Waves

Marine heatwave categories

European Zone

Marine heatwave categories forecast for 28 March, 2026. European zone. Credit: Mercator Ocean International

Mediterranean Sea

The marine heatwave in the basin is decreasing in intensity and in extent with few scattered areas with moderate category.

North Atlantic

The area covered by marine heatwaves in northwestern Europe is decreasing slightly, while their intensity remains stable with mostly in the moderate category.

Global Ocean

 

Marine heatwave categories forecast for 28 March, 2026. European zone. Credit: Mercator Ocean International

North Atlantic

The marine heatwave in the northeast Caribbean is also decreasing in area and remains stable in intensity. 

South Atlantic

The marine heatwave around 0°W 15°S is increasing in size and intensity, with strong to severe categories becoming widespread off the coast of Angola and Namibia.

North Pacific

The marine heatwave in the central-northern part of the basin around 180°W / 50°N increasing in intensity with moderate to strong categories. The marine heatwave in the center of the basin is increasing in intensity, with a large area classified as strong to severe. The surface area remains stable. The marine heatwave around California is stable in extent, but is increasing in intensity, with both strong to sever categories. 

South Pacific

The marine heatwave stretching from the west coast of South America to the center of the basin is decreasing in extent, with moderate and strong categories. The marine heatwave northeast of New Zealand is decreasing in extent with the moderate category. 

Southern Ocean

The marine heatwave between 50°E and 110°E remains stable in area and is increasing in intensity, with mainly strong and some severe categories.

 

Weekly temperature anomalies

Average sea surface temperature anomalies in Europe region and in the global ocean for the week of the 22 to 28 March 2026.
Mediterranean Sea 0 °C to 1.5°C 
North Atlantic -3 °C to 3°C 
South Atlantic -3°C to 3°C 
North Pacific -3°C to >3°C 
South Pacific -1°C to 3°C  
Southern Ocean -0.5°C to 2°C 

Forecasts for 28 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