Tainan weather in May

May in Tainan: sweltering, soaked, with muggy air — a gamble, with 17 rainy days.

Updated September 2026 · climate normals from ERA5 reanalysis

Tainan🇹🇼 Taiwan · Taiwan & Okinawa · City52
  1. 85Jan
  2. 91Feb
  3. 82Mar
  4. 71Apr
  5. 52May
  6. 41Jun
  7. 45Jul
  8. 39Aug
  9. 55Sep
  10. 64Oct
  11. 76Nov
  12. 88Dec

#9 of 12 months in Tainan · #1265 of 1413 destinations to visit in May · comfort 52/100 (tier D)

Days
30°C
Nights
26°C
Wet days
17
Sun
9.7 h
Humidity
83%
Daylight
13 h
Tainan, Taiwan
Photo: Alan Wang · Pexels

Traveller notes on Tainan in May

Notes from nearby Alishan (83 km away)

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

Taiwan forum threads are direct that late May marks the start of the plum rain season, bringing rain on roughly half the days through the following weeks, with fog at Alishan described as an almost daily occurrence even outside heavy rain spells. The more typical pattern posters described was sunny mornings followed by afternoon thunderstorms lasting an hour or two before clearing again, rather than sustained all-day washouts. One specific frustration flagged repeatedly: the famous Alishan sunrise is genuinely hit-and-miss on foggy mornings, so visitors chasing it were advised to build in a backup morning if possible, and to always carry a proper rain jacket or poncho.
ChiayiMountainRegular · May · 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 — May

Daytime high30°C / 87°F🔥 sweltering
Nighttime low26°C / 78°F
Feels like (high)36°C / 97°F
Sea temperature28°C / 82°F😎 warm sea
Rainfall254 mm / 10 in⛈ soaked
Rainy days17 days
Humidity83%💦 very humid
Dew point23°C / 73°F
Sunshine9.7 h/day
Daylight13.2 h
Wind13 km/h / 8 mph
Air quality (US AQI)89🙂 moderate

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

Crowds in Tainan in May

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 2 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 May

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

  • Season

    Plum rain season

    1 May – 15 Jun · usuallyMonsoon

    The front that breaks the long southern dry spell, in heavy blocks rather than steady rain. It is also what fills the reservoirs this city argues about every spring.

What's on around the world in May →

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 May — FAQ

Is May a good time to visit Tainan?
May in Tainan: sweltering, soaked, with muggy air — a gamble, with 17 rainy days. It ranks #9 of 12 months for Tainan on SeasonMap's comfort score (52/100).
What is the weather like in Tainan in May?
In May, Tainan averages a daily high of 30.3°C and a low of 25.7°C, with about 253.9 mm of rain over roughly 17 rainy days.
What is the air quality in Tainan in May?
Tainan has a mean US Air Quality Index of about 89 in May.

Within 300 km: Alishan's Firefly season around 10 Apr – 15 May, and Sun Moon Lake's Firefly season around 1 Apr – 15 May.