Marine Heatwave Bulletin Forecasts for 6 September 2025- Reposted from Mercator Ocean International

Marine heatwave categories for 6 September, 2025. Global. Credit: Mercator Ocean International.

Key takeaways

  • Mediterranean Sea: The extent of the marine heatwave in the eastern basin increases, with moderate and strong categories still present. 
  • Tropical Atlantic: The intensity of the marine heatwaves around Cuba and in the Gulf of Mexico increases with strong to severe categories. 
  •  North Pacific: The marine heatwave in the Yellow Sea is increasing in intensity with the development of severe categories.
  • Indian Ocean: The marine heatwave around 0°S is decreasing in intensity and in extent.

Tropical Atlantic

The intensity of the marine heatwaves around Cuba and in the Gulf of Mexico increases and are now mainly in strong to severe category. The marine heatwave in the center of the basin around 60°W is decreasing in intensity and is now mostly in moderate category, with strong category locally.

Mean Sea Surface Temperature Anomalies for 31 August – 6 September, 2025. Credit: Mercator Ocean International.
North Atlantic -3°C to 2.5°C 
Tropical Atlantic  -1°C to 1.5°C 
Mediterranean Sea0°C to 1°C 
North Pacific-1.5°C to >3°C 
Indian -1°C à 2°C