SeasonMapYakushima (Yakushima National Park) weather in September
Japan
September in Yakushima: nice, soaked, with clean air — fine if you can take 18 rainy days.
#6 of 12 months in Yakushima · #996 of 1383 destinations to visit in September · comfort 67/100 (tier C)
Updated September 2026 · climate normals from ERA5 reanalysis
Traveller notes on Yakushima in September
Other months in Yakushima
Yakushima's forum flags October as still within typhoon season, which can run through late in the month, and warns that heavy rain — not unusual on this famously wet island — can shut the trails and turn the rivers dangerous. Regulars still rate it among the best hiking months when the weather cooperates, so it's worth building a flexible day or two into the plan.
Add your own note from Yakushima's card on the map.
Yakushima climate normals — September
| Daytime high | 22°C / 72°F | 😎 nice |
|---|---|---|
| Nighttime low | 21°C / 69°F | |
| Feels like (high) | 23°C / 73°F | |
| Sea temperature | 29°C / 85°F | ♨️ bath-warm |
| Rainfall | 207 mm / 8.1 in | ⛈ soaked |
| Rainy days | 18 days | |
| Humidity | 80% | 💦 very humid |
| Dew point | 18°C / 64°F | |
| Sunshine | 9.4 h/day | |
| Daylight | 12.3 h | |
| Wind | 33 km/h / 20 mph | |
| Air quality (US AQI) | 45 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Yakushima 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.
Shoulder seasonschool holidays in 3 of the markets that fill it, an ordinary month(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Yakushima'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 weatherYakushima's weather doesn't swing hard through the year — comfort stays fairly steady in every month.
What's on in Yakushima in September
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Hazard
Typhoon season
15 Jul – 15 Oct · usuallyClosuresThe ferry and the hydrofoil from Kagoshima stop a day before a storm and do not restart for a day after. Budget a spare day either end of a trip in this window. Source ↗
Where is Yakushima?
Yakushima in September — FAQ
- Is September a good time to visit Yakushima?
- September in Yakushima: nice, soaked, with clean air — fine if you can take 18 rainy days. It ranks #6 of 12 months for Yakushima on SeasonMap's comfort score (67/100).
- What is the weather like in Yakushima in September?
- In September, Yakushima averages a daily high of 22.4°C and a low of 20.5°C, with about 206.6 mm of rain over roughly 18.2 rainy days.
- What is the air quality in Yakushima in September?
- Yakushima has a mean US Air Quality Index of about 45 in September.