Marine heatwave categories

North Atlantic

The marine heatwave extending from the English Channel to the Bay of Biscay is intensifying and is now mostly in the “strong” category, with “severe” and “extreme” conditions in some areas. The marine heatwave off the coasts of Portugal and Morocco is intensifying, with “strong” conditions covering a larger area. The marine heatwave extending from the Caribbean to the central part of the basin is increasing in intensity and area around 50°W/30°N but decreasing in intensity around 30°W/30°N. The marine heatwave in the Gulf of Mexico remains stable in area but is decreasing in intensity, shifting overall from the moderate to strong category. The marine heatwave off the coast of Guinea is decreasing in intensity and area near the coast, where only a few scattered areas remain, but is increasing in intensity and area in the center of the basin around 30°W/10°N. 

 South Atlantic 

The marine heatwave stretching from Brazil to South Africa is decreasing in intensity and area.

Mediterranean Sea

The marine heatwaves affecting almost the entire basin are decreasing in intensity and area. Marine heat waves are mostly classified as moderate throughout the basin, except around Corsica and Sardinia where strong categories are persisting

Pacific Ocean

The marine heatwave, which extends across nearly the entire equatorial axis from 30°S to 25°N, is increasing in both area and intensity, particularly off the coasts of Ecuador, Peru, and Chile, where the “strong,” “severe,” and “extreme” categories are expanding in area, as well as near 180°W, where the “strong” category is expanding in area. The marine heatwave south of the Bering Sea (around 50°N) is decreasing in intensity and area but remains in the moderate to strong category. South of the basin, around 110°W/50°S, a moderate to strong marine heatwave is developing. In the Yellow Sea, a moderate-to-strong marine heatwave is developing. North of the island of Borneo, the marine heatwave is intensifying, with conditions mostly in the strong category and locally severe and extreme. 

Indian Ocean

The marine heatwave in the Bay of Bengal is decreasing in both area and intensity, with only a few scattered areas of moderate intensity remaining. To the northwest of the island of Sumatra, a marine heatwave of moderate to strong intensity is developing. To the northwest of Australia, a marine heatwave of moderate to strong intensity is developing. The remaining marine heatwaves in the Gulf of Arabia, the central Indian Ocean, and east of Madagascar are decreasing in area but remain generally stable in intensity, still ranging from moderate to strong. 

Weekly temperature anomalies

Mer Méditerranée	0°C à >3°C
Atlantique Nord	-3 °C à 3°C
Pacifique	-2°C à >3°C
Océan Indien	-1°C à 2°C
Atlantique Sud	-3°C à 3°C