Marine heatwave Bulletin
Forecasts for 25 July 2026​

Europe

 

Marine heatwave category forecasts for the July 25, 2026 around Europe. Data: GLO12 forecast. Source: Mercator Ocean International.

Mediterranean Sea

The marine heatwave extending from eastern Sardinia to Greece is shrinking in extent but remains generally stable in intensity, with conditions still ranging from moderate to strong. From Gibraltar to the Balearic Islands, the area affected by the strong category is shrinking in favor of the moderate category, but the marine heatwave is intensifying locally in the Alboran Sea, with the emergence of severe and extreme categories. 

North Atlantic

The marine heatwave affecting the area north of the British Isles is shrinking in extent, with only a few scattered areas classified as moderate to strong remaining.

Global Ocean

 

Marine heatwave category forecasts for the July 25, 2026 for the Global Ocean. Data: GLO12 forecast. Source: Mercator Ocean International.

North Atlantic

The marine heatwave extending from south of the British Isles and stretching across the Atlantic all the way to Florida, generally stable in area but is decreasing in intensity, with most areas now classified as moderate to strong. The marine heatwave in the Gulf of Mexico remains stable in intensity, with most areas still classified as moderate, but is decreasing in extent. 

Pacific Ocean

North : The marine heatwave in the southern Bering Sea (around 50°N) is expanding in extent but remains stable in intensity, with conditions still ranging from moderate to strong. The marine heatwave in the Sea of Japan is increasing in intensity and is now mostly in the strong category. 

Equatorial: The marine heatwave extending across nearly the entire equatorial axis from 30°S to 30°N remains generally stable in both area and intensity, with conditions still ranging from moderate to severe and locally extreme, except for the western part of this marine heatwave (from 180°E to 1550°E), which is increasing in intensity and is mostly moving into the strong to severe category, with locally extreme conditions. 

South : The marine heatwave south of New Zealand remains stable in both intensity and extent. 

Indian Ocean

Marine heatwaves in the basin (west of Madagascar, in the Arabian Sea, and in the central part of the basin) remain generally stable in terms of extent and intensity, with conditions still ranging from moderate to strong.

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.