Marine heatwave Bulletin Forecasts for April 18, 2026​ – Reposted from Mercator Ocean

SST Global April 18 2026

GLOBAL OCEAN

North Atlantic

The marine heatwave in the centre of the basin remains stable in terms of coverage and intensity, with only a few scattered areas classified as moderate and locally strong. 

South Atlantic

The marine heatwave off the coast of West Africa, extending from the equator to 30°S across the eastern half of the basin, remains generally stable in terms of coverage, with mostly moderate conditions and a few strong patches locally. 

North Pacific

The marine heatwave near 180°W and 50°N remains largely stable in extend, with severe conditions continuing to spread while strong and moderate conditions are still present. The marine heatwave off the North American coast is generally stable in both extent and intensity, with strong and moderate categories. The marine heatwave in the center of the basin is stable in terms of coverage, with strong conditions predominating. 

South Pacific

The marine heatwave along the coast of Chile is decreasing in both extent and intensity; the remaining large areas are classified as moderate. The marine heatwave near 120°W remains stable in extent, but its intensity is increasing, with areas classified as strong and moderate. 

Southern Ocean

The marine heatwave near 80°E remains stable in extent and in categories.

Weekly temperature anomalies

SST 7-Day Anomaly 4-18-2026
North Atlantic-3 °C – 3°C 
South Atlantic-2°C – 3°C 
North Pacific-2°C – >3°C 
South Pacific-1°C – 3°C  
Southern Ocean-0.5°C – 2°C