SeasonMapKumamoto weather in September
Japan
September in Kumamoto: warm, rainy, with clean air — a good time to visit.
#7 of 12 months in Kumamoto · #984 of 1383 destinations to visit in September · comfort 68/100 (tier C)
Updated September 2026 · climate normals from ERA5 reanalysis
Traveller notes on Kumamoto in September
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Kumamoto climate normals — September
| Daytime high | 28°C / 82°F | 🌤 warm |
|---|---|---|
| Nighttime low | 22°C / 72°F | |
| Sea temperature | 28°C / 83°F | ♨️ bath-warm |
| Rainfall | 134 mm / 5.3 in | 🌧 rainy |
| Rainy days | 13 days | |
| Humidity | 81% | 💦 very humid |
| Dew point | 22°C / 71°F | |
| Sunshine | 8.4 h/day | |
| Daylight | 12.4 h | |
| Wind | 13 km/h / 8 mph | |
| Air quality (US AQI) | 47 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Kumamoto 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.
BusyFujisaki Hachimangu autumn festival, school holidays in 3 of the markets that fill it(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Kumamoto'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 weatherKumamoto's best weather comes in April, October and November — separate windows, not one continuous season.
Best weatherFair weatherToughest weather
What's on in Kumamoto in September
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Hazard
Mount Aso crater alerts
1 Jan – 31 DecVolcanic activityClosuresNakadake is the day trip everyone books and the one that gets cancelled: the crater rim closes without notice on gas readings or a raised alert, and has been shut for long stretches. Check before you drive out. Source ↗
- Hazard
Typhoon season
1 Aug – 30 Sep · usuallyClosuresKyushu takes more direct hits than anywhere else in Japan and a landfall stops the trains and the airport for a day. Storms are not spread evenly through the year and these are the two months. Source ↗
- Festival
Fujisaki Hachimangu autumn festival
10–20 Sep · usuallyMajor festivalCrowdedThe city's own festival, run around decorated horses and a drumming crowd that walks them through the centre for hours. Roads shut and the whole place turns out for it. Source ↗
Nearby, and something's on
Within 300 km of Kumamoto — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Kumamoto?
Kumamoto in September — FAQ
- Is September a good time to visit Kumamoto?
- September in Kumamoto: warm, rainy, with clean air — a good time to visit. It ranks #7 of 12 months for Kumamoto on SeasonMap's comfort score (68/100).
- What is the weather like in Kumamoto in September?
- In September, Kumamoto averages a daily high of 28°C and a low of 22.1°C, with about 134 mm of rain over roughly 12.6 rainy days.
- What is the air quality in Kumamoto in September?
- Kumamoto has a mean US Air Quality Index of about 47 in September.
Other months in Kumamoto
Compare Kumamoto in September
Warmer or cooler than Kumamoto in September
Similar destinations in East Asia — September
Within 300 km: Hiroshima's Miyajima visitor tax on 1 Jan – 31 Dec, and Busan's Chuseok on 24–26 Sep.