SeasonMapSun Moon Lake (Yuchi) weather in September
Taiwan
September in Sun Moon Lake: hot, soaked, with muggy air — a gamble, with 25 rainy days.
#12 of 12 months in Sun Moon Lake · #1236 of 1383 destinations to visit in September · comfort 51/100 (tier D)
Updated September 2026 · climate normals from ERA5 reanalysis
Traveller notes on Sun Moon Lake in September
Other months in Sun Moon Lake
Sun Moon Lake's forum flags January and the other cooler months for fog — regulars describe it as a genuine hit-or-miss attraction depending on the day, since mist can roll in and cut the view. One recent visitor got lucky with plenty of sun and called the quieter winter atmosphere a different, still worthwhile kind of beautiful.
Add your own note from Sun Moon Lake's card on the map.
Sun Moon Lake climate normals — September
| Daytime high | 25°C / 78°F | 🥵 hot |
|---|---|---|
| Nighttime low | 19°C / 66°F | |
| Feels like (high) | 30°C / 86°F | |
| Rainfall | 332 mm / 13.1 in | ⛈ soaked |
| Rainy days | 25 days | |
| Humidity | 88% | 💦 very humid |
| Dew point | 20°C / 68°F | |
| Sunshine | 9.4 h/day | |
| Daylight | 12.3 h | |
| Wind | 5 km/h / 3 mph | |
| Air quality (US AQI) | 92 | 🙂 moderate |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Sun Moon Lake 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.
BusyCross-lake Swimming Carnival, school holidays in 3 of the markets that fill it(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Sun Moon Lake'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).
Toughest weatherSun Moon Lake's weather peaks December–February.
September coincides with Typhoon season.
Best weatherFair weatherToughest weather
What's on in Sun Moon Lake in September
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Hazard
Typhoon season
1 Jul – 15 Oct · usuallyClosuresInland and high, so it is the rain rather than the wind that does the damage. Landslides close the mountain roads in and out for days at a time. Source ↗
- Festival
Cross-lake Swimming Carnival
10 Sep – 5 Oct · usuallyMajor festivalCrowdedBook earlyThe one day of the year swimming in the lake is allowed, and more than twenty thousand people take it. Entries open months ahead and every room around the shore goes with them. Source ↗
- Season
Wet season
MonsoonRisk25 rainy days and about 332 mm in the month — the real kind of rainy season, not afternoon showers.
from the climate normals
Nearby, and something's on
Within 300 km of Sun Moon Lake — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Sun Moon Lake?
Sun Moon Lake in September — FAQ
- Is September a good time to visit Sun Moon Lake?
- September in Sun Moon Lake: hot, soaked, with muggy air — a gamble, with 25 rainy days. It ranks #12 of 12 months for Sun Moon Lake on SeasonMap's comfort score (51/100).
- What is the weather like in Sun Moon Lake in September?
- In September, Sun Moon Lake averages a daily high of 25.4°C and a low of 19°C, with about 332.4 mm of rain over roughly 25.2 rainy days.
- What is the air quality in Sun Moon Lake in September?
- Sun Moon Lake has a mean US Air Quality Index of about 92 in September.
Other months in Sun Moon Lake
Compare Sun Moon Lake in September
Warmer or cooler than Sun Moon Lake in September
Similar destinations in East Asia — September
Within 300 km: Kenting's Raptor migration around 25 Sep – 25 Oct, and Taipei's Ghost Month around 5 Aug – 15 Sep.