Marine heatwave category forecasts for July 18 2026. Europe region. Data: GLO12 forecast. Source: Mercator Ocean International.
The extent and intensity of marine heatwaves covering nearly the entire western Mediterranean basin are increasing overall, from the Strait of Gibraltar to Greece. Strong-category heatwaves predominate, with a few severe-category events occurring locally, particularly in eastern Tunisia.
The marine heatwave covering the entire European Atlantic coast—from Great Britain to the Canary Islands off the coast of Morocco—and extending offshore is growing in both area and intensity. Most areas are classified as strong or severe, with a few extreme zones off the Bay of Biscay and in northwestern Spain.
A marine heatwave spanning approximately 10° of latitude stretches from the coast of Florida to the central Atlantic around 30°W. Its intensity is increasing, with mostly strong and locally severe conditions. The marine heatwave in the Gulf of Mexico is decreasing in both intensity and area; a few moderate and strong categories remain in the northern Gulf.
The marine heatwave in the southern Bering Sea is decreasing in area but increasing in intensity, with an equal number of strong and moderate categories. The marine heatwave in the Sea of Japan is decreasing in both area and intensity. The marine heatwave extending across nearly the entire equatorial band from 15°S to 20°N is increasing in both area and intensity. Strong to severe categories persist off the coast of Central America and also extend around 15°N between 140° and 180°W longitude, with a few patches of extreme category in this area. The heatwave between 90°W and 120°W is stable in area but is increasing in intensity, with more strong categories. It is tending to form a relatively homogeneous system with the one present in the equatorial band. The marine heatwaves in the inland seas of the Philippines are decreasing in both area and intensity. The marine heatwave south of New Zealand remains stable in both intensity and area.
The marine heatwave in the northeastern part of the basin, near the Cocos Islands, remains generally stable in terms of coverage but is increasing in intensity locally, with a mix of moderate and strong conditions.
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.
Weekly temperature anomalies for the week 12 – 18 June 2026
Weekly sea surface temperature anomaly map for the period 12–18 July 2026. Europe (above) and Global Ocean (bottom). GLO12 forecasts. Source: Mercator Ocean International.
| Mediterranean Sea | 0°C to >3°C |
| North Atlantic | -3 °C to >3°C |
| North Pacific | -2°C to >3°C |
| South Pacific | -1°C to >3°C |
| Southern Ocean | -1°C to 1.5°C |
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Datasets and products: Global Ocean Physics Analysis and Forecast (sea surface temperature) E.U. Copernicus Marine Service/ Mercator Ocean International. https://doi.org/10.48670/moi-00016
