SeasonMapDouglas weather in September
Isle of Man
September in Douglas: nice, rainy, with clean air — a great time to visit.
#5 of 12 months in Douglas · #793 of 1383 destinations to visit in September · comfort 77/100 (tier B)
Updated September 2026 · climate normals from ERA5 reanalysis
Traveller notes on Douglas in September
No notes yet. Open Douglas on the map to add the first one.
Douglas climate normals — September
| Daytime high | 16°C / 61°F | 😎 nice |
|---|---|---|
| Nighttime low | 14°C / 57°F | |
| Sea temperature | 17°C / 62°F | 🧊 bracing |
| Rainfall | 114 mm / 4.5 in | 🌧 rainy |
| Rainy days | 15 days | |
| Humidity | 81% | 💦 very humid |
| Dew point | 12°C / 54°F | |
| Sunshine | 8.1 h/day | |
| Daylight | 12.7 h | |
| Wind | 36 km/h / 23 mph | |
| Air quality (US AQI) | 40 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Douglas 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.
BusyManx Grand Prix, school holidays in 3 of the markets that fill it(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Douglas'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 weatherDouglas's weather peaks June–August, best around July.
Best weatherFair weatherToughest weather
What's on in Douglas in September
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Festival
Manx Grand Prix
16 Aug – 5 Sep · usuallyMotorsport weekendCrowdedClosuresThe same Mountain Course at the end of August, run for amateurs and newcomers and with the classic bikes alongside. Far less pressure on rooms than the TT, and the same road closures to plan around. Source ↗
Nearby, and something's on
Within 300 km of Douglas — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Douglas?
Douglas in September — FAQ
- Is September a good time to visit Douglas?
- September in Douglas: nice, rainy, with clean air — a great time to visit. It ranks #5 of 12 months for Douglas on SeasonMap's comfort score (77/100).
- What is the weather like in Douglas in September?
- In September, Douglas averages a daily high of 16.1°C and a low of 14°C, with about 114.1 mm of rain over roughly 14.8 rainy days.
- What is the air quality in Douglas in September?
- Douglas has a mean US Air Quality Index of about 40 in September.
Other months in Douglas
Compare Douglas in September
Warmer or cooler than Douglas in September
Similar destinations in Northern Europe — September
Within 300 km: Belfast's Culture Night on 18 Sep, and Liverpool's International Beatleweek on 26 Aug – 1 Sep.