Tainan weather in September

September in Tainan: sweltering, soaked, with muggy air — a gamble, with 12 rainy days.

Updated September 2026 · climate normals from ERA5 reanalysis

Tainan🇹🇼 Taiwan · Taiwan & Okinawa · City55
  1. 85Jan
  2. 91Feb
  3. 82Mar
  4. 71Apr
  5. 52May
  6. 41Jun
  7. 45Jul
  8. 39Aug
  9. 55Sep
  10. 64Oct
  11. 76Nov
  12. 88Dec

#8 of 12 months in Tainan · #1218 of 1413 destinations to visit in September · comfort 55/100 (tier D)

Days
32°C
Nights
27°C
Wet days
12
Sun
9.8 h
Humidity
84%
Daylight
12 h
Tainan, Taiwan
Photo: Alan Wang · Pexels

Traveller notes on Tainan in September

Notes from nearby Alishan (83 km away)

Tainan doesn't have its own notes for September yet — these are about Alishan, close enough to share the season.

Alishan-forum threads on sunrise viewing are direct results here are genuinely inconsistent, one traveler reporting a great sunset but an underwhelming, cloudless sunrise the same trip, another describing thick fog ruining the sunrise while catching a genuine sea of clouds elsewhere on the same itinerary. Posters call September part of the broader wet season, a real chance of lingering shower activity even as the worst of typhoon season winds down. Regulars recommend building at least two mornings into any stay to improve the odds of catching a clear sunrise, a single attempt genuinely a gamble this time of year. Layers are standing advice given how much temperatures swing between a mild afternoon and a genuinely cold pre-dawn wait. Posters call the forest railway and cypress groves worth the trip regardless of whether sunrise cooperates. The record: 19.2C days feeling like 20C, 13.4C nights, an extraordinarily high 219mm across nearly 23 days and 88 percent humidity.
AlishanSeptemberRegular · September · 1 month ago · about Alishan · Read more on Tripadvisor ↗

Other months in Tainan

Forum posters describe July and August as Taiwan's hottest months, typically 33-36C with high humidity, and afternoon thundershowers a regular feature of the June-August stretch. Posters are consistent that August sits within typhoon season (June-October), with August, July and September the three months most likely to see a storm make landfall - roughly three to four typhoons affect Taiwan in an average season, and a direct hit during a trip can cost travelers one to two disrupted days. Posters are equally clear that summer travel remains genuinely popular despite the heat, pointing to Taiwan's excellent air-conditioned MRT, malls and convenience stores, plus shaved ice and bubble tea on seemingly every corner, as real relief options. Posters generally rate August as hot, humid and typhoon-season for Tainan, entirely workable with flexible plans and frequent air-conditioned breaks.
Tripadvisor community · August · 1 month ago · Read more on Tripadvisor ↗
Forum posters describe February in southern Taiwan as cool and pleasant, typically 15-20C, milder than the 10-15C posters report further north - winter here is generally mild outside the high mountains. It's not officially the rainy season, but posters note rain remains a real possibility on any given day, so a light jacket that also handles rain is standard packing advice. Cold fronts can occasionally push temperatures down to around 6C for a couple of days, a real but temporary dip rather than the norm. Posters describe February overall as the tail end of winter with spring clearly approaching, milder than most visitors expect coming from more northerly climates.
Tripadvisor community · February · 1 month ago · Read more on Tripadvisor ↗

Add your own note from Tainan's card on the map.

Tainan climate normals — September

Daytime high32°C / 89°F🔥 sweltering
Nighttime low27°C / 80°F
Feels like (high)38°C / 100°F
Sea temperature30°C / 86°F♨️ bath-warm
Rainfall201 mm / 7.9 in⛈ soaked
Rainy days12 days
Humidity84%💦 very humid
Dew point24°C / 74°F
Sunshine9.8 h/day
Daylight12.3 h
Wind13 km/h / 8 mph
Air quality (US AQI)88🙂 moderate

Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.

Crowds in Tainan 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)

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Peak crowdsBusyShoulder seasonQuiet

Best months for Tainan'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 weatherTainan's weather peaks December–February.

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Best weatherFair weatherToughest weather

What's on in Tainan in September

Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.

  • Hazard

    Typhoon season

    1 Jul – 15 Oct · usuallyClosures

    Fewer direct hits than the east coast, but the flooding is the problem here rather than the wind. A declared typhoon day closes everything, including the temples. Source ↗

What's on around the world in September →

Nearby, and something's on

Within 300 km of Tainan — a day trip or a short hop — with something on this month. Never part of the comfort score.

Where is Tainan?

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Tainan in September — FAQ

Is September a good time to visit Tainan?
September in Tainan: sweltering, soaked, with muggy air — a gamble, with 12 rainy days. It ranks #8 of 12 months for Tainan on SeasonMap's comfort score (55/100).
What is the weather like in Tainan in September?
In September, Tainan averages a daily high of 31.6°C and a low of 26.8°C, with about 201 mm of rain over roughly 12.3 rainy days.
What is the air quality in Tainan in September?
Tainan has a mean US Air Quality Index of about 88 in September.

Within 300 km: Sun Moon Lake's Cross-lake Swimming Carnival around 10 Sep – 5 Oct, and Kenting's Raptor migration around 25 Sep – 25 Oct.