When to expect it editorial
When is sargassum season?
The short version: it builds through spring, peaks in summer, and eases in fall. The catch: any given year, island, or beach can break the pattern, and a bad year can start early. Use the calendar to set expectations, then check current conditions before you commit.
January and February: usually your calmest window
The Atlantic belt is often just starting to form, and Caribbean beaches typically see the least of it. That is a regional tendency, not a promise for your specific beach, but if a clear shoreline is the whole point of the trip, these months give you the best starting odds. NOAA CoastWatch FAQ.
March and April: the season builds (spring breakers, this is you)
Winds and currents start pushing the belt toward the Caribbean in late winter and early spring. More seaweed offshore means better odds of it landing somewhere, but nobody can name the beach or the date in advance. This is the window where checking current conditions before you commit pays off most. NOAA/AOML overview.
May through August: peak seaweed season
NOAA's regional guidance points to a May-July peak for many Caribbean communities, with heavy transport continuing through summer. Booking a windward coast in this window is the highest-stakes bet on the calendar; leeward coasts and a good cleanup operation matter most now. NOAA Sargassum Inundation Events addendum.
September through December: winding down
Amounts usually ease into fall and winter, though the timing shifts year to year and local landings still happen. NOAA is blunt that exact beaching paths stay hard to predict, so a quick conditions check before travel is still worth it. NOAA CoastWatch FAQ.