Marine heatwave Bulletin
Forecasts for 22 August 2026​

European Zone

 

Marine heatwave category forecasts for 22 August, 2026 for the European Zone. Data: GLO12 forecast. Source: Copernicus Marine Service/Mercator Ocean International.

Mediterranean Sea

The marine heatwave affecting the entire Mediterranean basin continues to decrease in area but is intensifying south of Sicily, with almost exclusively strong categories. There is virtually none left in the east, starting from the southern tip of Greece; the heatwaves off the southern coast of France and near Gibraltar have almost disappeared.   The areas of persistent heatwaves across the rest of the basin are mostly classified as “strong”. 

North Atlantic

The marine heatwave in the North Atlantic is shrinking in area but, more importantly, in intensity. Only a few areas remain in the “strong” category—north of Spain, around the Canary Islands, and in the central part of the basin around 30°N—while the rest have been downgraded to “moderate”.

 

Global Ocean

Marine heatwave category forecasts for 22 August, 2026 for the Global Ocean. Data: GLO12 forecast. Source: Copernicus Marine Service/Mercator Ocean International.

Pacific Ocean

• The marine heatwave south of the Bering Sea (around 50°N), which extends as far as northern Japan, remains fairly stable in terms of area but is intensifying, particularly in northeastern Japan, where conditions are severe and locally extreme. 
• A strong marine heatwave is developing in the Yellow Sea between South Korea and Beijing. 
• The marine heatwave extending across nearly the entire equatorial axis from 30°S to 25°N is expanding slightly in area toward the northwest (around 170°E) but, more importantly, in intensity, particularly along the coasts of Peru, Ecuador, and Colombia out to sea around 130°W, where several areas are reaching severe and extreme categories. The proportion of strong categories also remains significant. 
• The marine heatwave west and south of New Zealand remains stable in both area and intensity.  

Indian Ocean

The marine heatwave west of Madagascar remains stable in both area and intensity, with mostly strong-category conditions. Moderate marine heatwaves are developing around the Seychelles and extending to the Maldives. Meanwhile, the heatwave in the center of the basin, south of Sri Lanka, is expanding slightly northward and has intensified to a strong category. 

Southern Ocean

The marine heatwave, extending from 50°E to 80°E in longitude and 45°S to 60°S in latitude, remains stable in both area and intensity, with conditions still ranging from moderate to strong.