Sargassum at Saint-Jean Beach: today's conditions
Moderate
A few patches
Saint-Jean sits on the northern shore of Saint-Barthélemy, in the wide bay running alongside the airport runway. A rocky point splits the sand into two halves and the water stays shallow well offshore, which is why the bay is busy from morning to sunset.
This page tracks sargassum at Saint-Jean and nothing else: what the beach looks like today, a 0 to 5 rating that sums it up at a glance, and a map placing Saint-Jean among the beaches around it. Everything is refreshed each morning, so you plan with today's picture instead of last season's photos.
Plage de Saint-Jean on the sargassum map
What to know about this beach
Saint-Jean faces due north, on the windward side of the island. That angle lines the bay up with north and northeast swells, the ones that carry drifting sargassum rafts toward shore. The easterly trades cross the bay sideways rather than blowing straight in, so weed that arrives tends to travel along the sand as much as it piles up in one place.
The shallow reef flat closing part of the bay cuts both ways. It holds back some of what approaches offshore, yet anything clearing it settles into slow, shallow water that flushes out gradually. The two ends of the beach, tucked in behind rock, usually keep a deposit longer than the open middle section. The daily rating reflects that layout rather than a general figure for the island.
Frequently asked questions
Why does sargassum reach Saint-Jean?
The bay opens due north, on the exposed side of the island, so north and northeast swells can push drifting rafts straight in. The reef flat offshore stops part of it, not all of it.
How do I check Saint-Jean before going down?
Open this page before you leave. The 0 to 5 rating and the FanGass map are recalculated every morning for Saint-Jean, and the same view shows how the neighbouring beaches are doing.
When is sargassum most likely in St Barts?
Landings usually cluster between spring and autumn, with peaks that shift from one year to the next. No calendar predicts a given week, which is why the daily reading matters more than the season.
Does the airport runway affect the seaweed here?
No. The runway borders the bay but plays no part in where weed lands. At Saint-Jean the factors are the northern opening, the reef flat offshore and the wind blowing that morning.