Tainan weather in September

In September, Tainan sees average daytime highs of 31°C and overnight lows near 26°C, with 184 mm of rain across 13.6 wet days and about 12.1 hours of daylight. It is the 4th-warmest and 5th-wettest month of the year here.

Day-to-day highs hold fairly steady near 31°C through the month. The sky is clear or mostly clear about 28% of the time in September, and the air most often feels miserable.

Daylight stretches from about 12 h 30 min at the start of September to 11 h 48 min by month's end. Set against the rest of the year, September is Tainan's 8th-clearest and 11th-windiest month. For the whole year in context, see Tainan's year-round climate.

Daytime high
31°
4th warmest
Overnight low
26°
9th coldest
Rainfall
184 mm
13.6 wet days
Daylight
12 h 06 min
5:50 AM – 5:57 PM
Cloud cover
63%
8th clearest
Wind
8 km/h
11th windiest
Solar energy
4.98 kWh/m²
Travel score
4.1
out of 10

Tainan is city in southern Taiwan.

Density
847/km²
people per km²
Founded
1624

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 31°C through the month.

A typical September day in Tainan reaches about 31°C in the afternoon and slips back to 26°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 29°C and 32°C. Set against its neighbours, September runs on par with August and about 2°C warmer than October.

20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
13126
23126
33126
43126
53126
63126
73126
83126
93126
103126
113126
123126
133126
143126
153126
163126
173126
183126
193126
203126
213126
223126
233126
243125
253125
263125
273125
283125
293125
303025

How September really feels in Tainan

Once humidity and wind are folded in, September averages 30 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
30
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

The story in September is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Tainan weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan22° / 16°497.210.77.4
Feb23° / 17°447.811.27.3
Mar25° / 19°589.211.87.0
Apr28° / 22°12011.812.55.8
May30° / 25°29918.713.14.0
Jun31° / 26°39319.713.43.2
Jul32° / 27°30519.113.33.2
Aug31° / 26°40121.112.83.2
Sep31° / 26°18413.612.14.1
Oct29° / 24°546.411.55.9
Nov27° / 21°415.710.97.3
Dec24° / 18°476.410.67.7

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 28% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 18% of September, with mostly cloudy or overcast conditions the remaining 54%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13268
23268
33268
43367
53565
63565
73763
83961
93961
104159
114258
124456
134555
144555
154753
164753
174852
184852
195050
205050
215149
225347
235446
245545
255644
265842
275842
285941
296040
306139

Chance of precipitation in September

Any precipitation

Tainan gets around 184 mm of rain over 13.6 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 46% and peaks near 64% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
164
263
362
461
560
658
756
855
953
1051
1150
1248
1347
1446
1544
1643
1742
1841
1941
2040
2139
2238
2337
2436
2535
2634
2733
2832
2931
3030

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

Most of September feels miserable — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, September lands in the miserable band about 75% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Muggy (%)Oppressive (%)Miserable (%)
10793
20892
30892
41990
511089
611188
711287
811386
911485
1011584
1111782
1221880
1322078
1422177
1522276
1622474
1722573
1832671
1932770
2032869
2142967
2243066
2353164
2453263
2563361
2663361
2773459
2883458
2983557
3093556

Wind in September

Winds average 8 km/h in September.

Across September, daily wind ranges from about 8 km/h on the calmest days to 8 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
18calm
28calm
38calm
48calm
58calm
68calm
78calm
88calm
98calm
108calm
118calm
128calm
138calm
148calm
158calm
168calm
178calm
188calm
198calm
208calm
218calm
228calm
238calm
248calm
258calm
268calm
278calm
288calm
298calm
308calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 30 min at the start of September to 11 h 48 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 42 minutes over September. Sunrise moves from 5:45 AM to 5:54 AM, and sunset from 6:13 PM to 5:43 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.55:456:13
212.45:456:12
312.45:456:11
412.45:466:10
512.45:466:09
612.45:466:08
712.35:476:07
812.35:476:06
912.35:476:05
1012.35:486:04
1112.25:486:03
1212.25:486:02
1312.25:496:01
1412.25:496:00
1512.25:495:58
1612.15:505:57
1712.15:505:56
1812.15:505:55
1912.15:505:54
2012.05:515:53
2112.05:515:52
2212.05:515:51
2312.05:525:50
2411.95:525:49
2511.95:525:48
2611.95:535:47
2711.95:535:46
2811.95:535:45
2911.85:545:44
3011.85:545:43

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.98 kWh/m².

For context, solar energy here swings from a low near 3.27 kWh/m² to a high of 5.43 kWh/m² in July across the year — September's 4.98 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
14.9Bright
24.9Bright
34.9Bright
44.9Bright
54.9Bright
65.0Bright
75.0Bright
85.0Bright
95.0Bright
105.0Bright
115.0Bright
125.0Bright
135.0Bright
145.0Bright
155.0Bright
165.0Bright
175.0Bright
185.0Bright
195.0Bright
205.0Bright
215.0Bright
224.9Bright
234.9Bright
244.9Bright
254.9Bright
264.9Bright
274.9Bright
284.8Bright
294.8Bright
304.8Bright
Planning a trip in September

Hazard calendar for Tainan

In seasonPeak

In September, Tainan sits inside its pacific typhoon and monsoon season. The full year is below, with each hazard's peak months called out.

Tainan sits in the Pacific typhoon belt; the season peaks July–October.

Tainan's monsoon runs May–September, when most of the year's rain falls.

Pacific typhoon
Monsoon
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is September a good time to visit Tainan?

Our two travel scores rate September for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

4.1
Sightseeing
8th-best month of the year
6.0
Beach & pool
6th-best month of the year

September is a reasonable time to visit Tainan for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Tainan in September

From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In September, Tainan sees daytime highs around 31°C and nights near 26°C. Pack light clothes and rain gear. Worth having: sun protection. About 14 days see rain.

light clothesrain gearsun protection

Sea temperature near Tainan in September

The nearest coast averages about 29°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 16 km away) is warmest in July at about 29°C and coldest in January near 24°C.

The water stays above 20°C all year — warm enough for a swim any month.

22°24°26°28°30°JanFebMarAprMayJunJulAugSepOctNovDecrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan24Refreshing
Feb24Refreshing
Mar24Warm
Apr26Warm
May28Warm
Jun29Tropical
Jul29Tropical
Aug29Tropical
Sep29Tropical
Oct28Warm
Nov26Warm
Dec25Warm

UV index in Tainan in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 11 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Tainan peaks around June 17 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 6 (high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecHighVery highExtremeVery highHighJun 17UV 12Dec 22UV 6
UV index (midday)Level
Jan6High
Feb8Very high
Mar10Very high
Apr9Very high
May9Very high
Jun12Extreme
Jul10Very high
Aug12Extreme
Sep11Extreme
Oct8Very high
Nov7Very high
Dec6High

Air quality in Tainan in September

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where September falls, not just the annual average.

Air quality in Tainan is worst in March — around 48 µg/m³ PM2.5 (poor), about 1.8× the cleanest month (July, 27 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0204060JanFebMarAprMayJunJulAugSepOctNovDecPoorModeratePoorMar 1848 µg/m³Jul 1828 µg/m³
PM2.5 (µg/m³)Level
Jan41Poor
Feb44Poor
Mar48Poor
Apr46Poor
May38Poor
Jun30Moderate
Jul27Moderate
Aug29Moderate
Sep38Poor
Oct40Poor
Nov40Poor
Dec36Poor
Location & terrain

Where is Tainan?

Tainan sits at 23.0°N, 120.2°E, 26 m above sea level, in Taiwan. The nearest listed city is Yongkang, 6.0 km away.

YujingXinyingKaohsiungFengshanBudaiTaibaoChiayi City

Topography around Tainan

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Tainan.

Within 3 km, the terrain around Tainan has only modest variations in elevation — a maximum elevation change of 40 m around an average of 20 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 136 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,645 m.

The land around Tainan is covered by artificial surfaces (86%) within 3 km, water (30%) and artificial surfaces (27%) within 16 km, and water (46%) and trees (37%) within 80 km.

3 km
40 m
16 km
136 m
80 km
3,645 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Yongkang 6.0 km · Yujing 29 km · Xinying 37 km · Kaohsiung 43 km · Fengshan 43 km · Budai 43 km · Taibao 54 km · Chiayi City 59 km

Taiwan travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type A / B
110 / 220 V · 60 Hz
Happiness
6.7 / 10
World Happiness, 2025
Religion
Buddhist 35%Taoist 33%none or unspecified 18%folk religion approximately 10%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Tainan (22.9908°, 120.2133°, elevation 26 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).