Atlantic Sargassum Bloom Expands Across Caribbean; Early Hurricane Forecast Predicts Typical Season

Rising levels of Sargassum seaweed across the Atlantic are pointing toward another major bloom year in 2026, even as early long-range forecasts suggest the upcoming Atlantic hurricane season may fall close to historical averages.

According to the University of South Florida Optical Oceanography Lab’s Sargassum Watch System (SaWS), Sargassum amounts reached record-high levels in February 2026. The latest SaWS monthly bulletin, released February 28, reported continued growth across the Western Caribbean, Western Atlantic, and Eastern Atlantic.

The forecast indicates that 2026 is expected to be a “major Sargassum year,” meaning total abundance is projected to exceed 75% of historical values. Beaching events are already occurring in parts of the region and are expected to increase along the windward sides of the Lesser Antilles and the Western Caribbean in the coming months. By contrast, levels in the Gulf of Mexico are projected to remain relatively low.

Additional monitoring tools support the outlook. NOAA CoastWatch and the collaborative Sargassum Inundation Risk product developed with the University of South Florida confirm that above-normal levels persisted through late February 2026, with continued growth expected in the near term.