As of today, out of season, returns ~November. Earth Exhibit tracks the live conditions and flags it the moment it is on.
Seasonal sea fog in Hạ Long Bay forms when cool, dry winter air and northeasterly monsoon flow interact with the relatively warm, humid surface waters of the Gulf of Tonkin.
The result is low-lying advection/radiation fog that often fills channels and wraps the bay's limestone karsts, producing dramatic low-cloud seascapes most mornings in the cool season.
Where to see it
A taste of where to see it. The full map, exact coordinates and the best timing for each spot live in the app.
| Viewing spots |
|---|
| Tuan Chau International Marina (main cruise departure) |
| Bãi Cháy / Bai Chay Bridge viewpoint (roadside/bridge pedestrian walkway) |
| + 1 more spot, with exact coordinates and timing, in the app → |
This is the short version
This page shows a taste. The app has the full list of where to see this, the exact timing, and live conditions for 1,000+ natural phenomena worldwide, so you know the moment one is genuinely worth the trip.