SeasonMapGustavia (St Barts) weather in September
Saint Barthélemy
September in Gustavia: warm, rainy, with clean air — an excellent time to visit.
#11 of 12 months in Gustavia · #599 of 1383 destinations to visit in September · comfort 83/100 (tier A)
Updated September 2026 · climate normals from ERA5 reanalysis
Traveller notes on Gustavia in September
No notes yet. Open Gustavia on the map to add the first one.
Gustavia climate normals — September
| Daytime high | 29°C / 83°F | 🌤 warm |
|---|---|---|
| Nighttime low | 27°C / 81°F | |
| Sea temperature | 30°C / 86°F | ♨️ bath-warm |
| Rainfall | 105 mm / 4.1 in | 🌧 rainy |
| Rainy days | 17 days | |
| Humidity | 80% | 💦 very humid |
| Dew point | 24°C / 76°F | |
| Sunshine | 10.9 h/day | |
| Daylight | 12.2 h | |
| Wind | 25 km/h / 16 mph | |
| Air quality (US AQI) | 38 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Gustavia in September
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
Quietschool holidays in 2 of the markets that fill it, one of its worst months for weather(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Gustavia's weather
Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).
Fair weatherGustavia's weather doesn't swing hard through the year — comfort stays fairly steady in every month.
What's on in Gustavia in September
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Hazard
Atlantic hurricane season
1 Jun – 30 NovMost of the season passes without incident, but this is the island Irma flattened in September 2017 and the rebuild took years. Mid-August to mid-October is the part of the window worth insuring against. Source ↗
- Season
Autumn shutdown
1 Sep – 31 OctOff-season shutdownClosuresSeptember and October are when the villas, the hotels and most of the good restaurants close for their annual break and the staff go home. Flights still run and the beaches are empty, but plan on eating wherever is open. Source ↗
Nearby, and something's on
Within 300 km of Gustavia — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Gustavia?
Gustavia in September — FAQ
- Is September a good time to visit Gustavia?
- September in Gustavia: warm, rainy, with clean air — an excellent time to visit. It ranks #11 of 12 months for Gustavia on SeasonMap's comfort score (83/100).
- What is the weather like in Gustavia in September?
- In September, Gustavia averages a daily high of 28.6°C and a low of 27°C, with about 105.2 mm of rain over roughly 16.8 rainy days.
- What is the air quality in Gustavia in September?
- Gustavia has a mean US Air Quality Index of about 38 in September.
Other months in Gustavia
Compare Gustavia in September
Warmer or cooler than Gustavia in September
Similar destinations in Caribbean — September
Within 300 km: Philipsburg's Sea turtle nesting around 1 Apr – 30 Nov.