A perspective for the Caribbean Sea and Gulf of America by University of South Florida Optical Oceanography Lab (bbarnes4@usf.edu, yuyuan@usf.edu, huc@usf.edu)

The map above shows the average Sargassum abundance for the month of July 2026, with warm colors representing higher abundance. The top color (red) indicates that 0.4% of the ocean surface is covered by Sargassum, meaning that Sargassum clumps and mats are scattered here and there in the location.

The Sargassum abundance for each region is compared with historical values in the same month of 2011–2025 in the whisker box plot below, where horizontal bars in each vertical box indicate minimal, 25%, 50%, 75%, and maximal historical values, respectively, for the month of June.

Consistent with most previous years, total Sargassum amount in every region started to decrease in July, while the distribution patterns remained stable. This is a good sign. However, total amount in the Gulf still remained at a record high for July, and in other regions was only second to the historical record in 2025, meaning that coastal inundation and beaching events in most regions continued in July, including the southeast coast of Florida and around the Caribbean and Lesser Antilles islands.

Looking ahead: Similar to previous years, Sargassum amount in most regions will continue to decrease in the coming months until possibly November. Meanwhile, beaching events around the Caribbean and southeast coast of Florida will continue, but likely not as severe as in June–July. Because the peak month is over, the year of 2026 is set to be the second largest Sargassum year, only second to 2025.

All previous monthly bulletins as well as daily imagery can be found under the Sargassum Watch System (SaWS). Meanwhile, high-resolution Sargassum maps for selected coastal regions are also available in near real-time under “Satellite Data Products => High Resolution” of the OOL Website.