Marine heatwave Bulletin Forecasts for October 18, 2025 by Mercator International

Global Ocean SST Oct 18 2025

Key Takeaways

  • Mediterranean sea – marine heatwaves remain stable at moderate categories.
  • Tropical Pacific – in the Philippine Sea the marine heatwave is increasing in area, with the emergence of strong categories. 
  • Tropical Atlantic – The marine heatwave present in the Gulf of Mexico and the Caribbean Sea remains stable with strong categories. The marine heatwave located around 30°W and near the equator is decreasing, with only a few scattered areas persisting.
Ocean SST Anomaly Oct 18 2025
Mediterranean Sea-1°C à 2°C 
Tropical Atlantic-1°C à 1.5°C 
North Pacific – 3°C < 3°C 
Tropical Pacific-2°C à 2.5°C 
India Ocean-1°C à 1.5°C