SeasonMapJamestown weather in September
Saint Helena
September in Jamestown: nice, dry, with muggy air — an excellent time to visit.
#12 of 12 months in Jamestown · #367 of 1383 destinations to visit in September · comfort 87/100 (tier A)
Updated September 2026 · climate normals from ERA5 reanalysis
Traveller notes on Jamestown in September
No notes yet. Open Jamestown on the map to add the first one.
Jamestown climate normals — September
| Daytime high | 20°C / 67°F | 😎 nice |
|---|---|---|
| Nighttime low | 19°C / 66°F | |
| Sea temperature | 20°C / 68°F | 🌊 fresh |
| Rainfall | 3 mm / 0.1 in | ☀️ dry |
| Rainy days | 0 days | |
| Humidity | 76% | 💦 very humid |
| Dew point | 14°C / 58°F | |
| Sunshine | 10.3 h/day | |
| Daylight | 12 h | |
| Wind | 34 km/h / 21 mph | |
| Air quality (US AQI) | 62 | 🙂 moderate |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Jamestown 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 Jamestown'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 weatherJamestown's weather doesn't swing hard through the year — comfort stays fairly steady in every month.
What's on in Jamestown in September
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Nature
Humpback whales
15 Jun – 15 Dec · usuallyWhale seasonHumpbacks use the island's waters through the southern winter and spring, with mothers and calves close in along the lee coast. Sightings are opportunistic rather than scheduled.
Where is Jamestown?
Jamestown in September — FAQ
- Is September a good time to visit Jamestown?
- September in Jamestown: nice, dry, with muggy air — an excellent time to visit. It ranks #12 of 12 months for Jamestown on SeasonMap's comfort score (87/100).
- What is the weather like in Jamestown in September?
- In September, Jamestown averages a daily high of 19.5°C and a low of 18.8°C, with about 2.6 mm of rain over roughly 0.2 rainy days.
- What is the air quality in Jamestown in September?
- Jamestown has a mean US Air Quality Index of about 62 in September.