Surat Thani weather in September

In September, Surat Thani sees average daytime highs of 31°C and overnight lows near 25°C, with 155 mm of rain across 23.7 wet days and about 12.1 hours of daylight. It is the 8th-warmest and 3rd-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 3% of the time in September, and the air most often feels miserable.

Daylight stretches from about 12 h 12 min at the start of September to 11 h 54 min by month's end. Set against the rest of the year, September is Surat Thani's 11th-clearest and 8th-windiest month. For the whole year in context, see Surat Thani's year-round climate.

Daytime high
31°
8th warmest
Overnight low
25°
6th coldest
Rainfall
155 mm
23.7 wet days
Daylight
12 hours
6:15 AM – 6:18 PM
Cloud cover
86%
11th clearest
Wind
10 km/h
8th windiest
Solar energy
4.89 kWh/m²
Travel score
2.9
out of 10

Surat Thani is city in Surat Thani province, Thailand.

Air quality
Elevated
PM2.5 17 µg/m³ · 2019
Density
1,914/km²
people per km²
Founded
1930

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 Surat Thani reaches about 31°C in the afternoon and slips back to 25°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 29°C and 33°C. Set against its neighbours, September runs about 1°C cooler than August and about 1°C warmer than October.

20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
13125
23125
33125
43125
53125
63125
73125
83125
93125
103125
113125
123125
133125
143125
153125
163125
173125
183125
193125
203125
213125
223125
233125
243125
253025
263025
273025
283025
293025
303025

How September really feels in Surat Thani

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.

Surat Thani weather by month

How September compares with the rest of the year at a glance. September is the 8th-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan30° / 24°699.511.55.3
Feb31° / 25°314.811.75.2
Mar32° / 25°929.211.94.1
Apr33° / 26°11414.412.23.2
May32° / 26°12422.112.42.6
Jun32° / 26°9518.712.53.0
Jul32° / 26°8918.512.53.2
Aug32° / 26°10819.812.33.1
Sep31° / 25°15523.712.12.9
Oct30° / 25°26827.311.83.0
Nov29° / 25°26723.511.63.5
Dec29° / 25°14915.711.54.7

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 3% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 6% of September, with mostly cloudy or overcast conditions the remaining 91%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1991
2991
3991
4991
51090
61090
71090
81090
91090
101090
111090
121090
131090
141090
151090
161090
17991
18991
19991
201090
211090
22991
23991
24991
25991
26991
27991
28892
29892
30892

Chance of precipitation in September

Any precipitation

Surat Thani gets around 155 mm of rain over 23.7 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 80% and peaks near 88% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%100%151015202530
Rain chance (%)
173
273
373
474
574
674
775
875
976
1076
1177
1278
1378
1479
1579
1680
1780
1881
1982
2082
2183
2283
2384
2484
2585
2685
2786
2887
2987
3088

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 56% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Oppressive (%)Miserable (%)
15248
25149
35149
45149
55149
65149
75149
85050
95050
105050
115050
124951
134852
144753
154654
164555
174456
184357
194258
204159
214060
223961
233862
243862
253763
263664
273664
283565
293466
303466

Wind in September

Winds average 10 km/h in September.

Across September, daily wind ranges from about 8 km/h on the calmest days to 10 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
110calm
210calm
310calm
410calm
510calm
610calm
710calm
810calm
910calm
1010calm
1110calm
1210calm
1310calm
1410calm
1510calm
1610calm
1710calm
1810calm
1910calm
2010calm
219calm
229calm
239calm
249calm
259calm
269calm
279calm
289calm
299calm
308calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 12 min at the start of September to 11 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 18 minutes over September. Sunrise moves from 6:17 AM to 6:14 AM, and sunset from 6:28 PM to 6:10 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.26:176:28
212.26:176:27
312.26:176:27
412.26:176:26
512.16:176:25
612.16:176:25
712.16:166:24
812.16:166:23
912.16:166:23
1012.16:166:22
1112.16:166:22
1212.16:166:21
1312.16:166:20
1412.16:166:20
1512.16:166:19
1612.06:156:18
1712.06:156:18
1812.06:156:17
1912.06:156:17
2012.06:156:16
2112.06:156:15
2212.06:156:15
2312.06:156:14
2412.06:156:13
2512.06:156:13
2612.06:146:12
2712.06:146:12
2811.96:146:11
2911.96:146:10
3011.96:146:10

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.89 kWh/m².

For context, solar energy here swings from a low near 4.14 kWh/m² to a high of 6.26 kWh/m² in March across the year — September's 4.89 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.0Bright
25.0Bright
35.0Bright
45.0Bright
55.0Bright
65.0Bright
75.0Bright
85.0Bright
95.0Bright
104.9Bright
114.9Bright
124.9Bright
134.9Bright
144.9Bright
154.8Bright
164.8Bright
174.8Bright
184.8Bright
194.8Bright
204.8Bright
214.8Bright
224.8Bright
234.8Bright
244.8Bright
254.8Bright
264.7Bright
274.7Bright
284.7Bright
294.7Bright
304.7Bright
Planning a trip in September

Hazard calendar for Surat Thani

In seasonPeak

In September, Surat Thani sits inside its cyclone and rainy season season. The full year is below, with each hazard's peak months called out.

Surat Thani sits in the North Indian Ocean cyclone zone; the season peaks May and October–November.

Surat Thani's rainy season runs September–December, when most of the year's rain falls.

Cyclone
Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is September a good time to visit Surat Thani?

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

2.9
Sightseeing
11th-best month of the year
4.2
Beach & pool
11th-best month of the year

September is a weaker month for outdoor sightseeing in Surat Thani.

What to pack for Surat Thani in September

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

In September, Surat Thani sees daytime highs around 31°C and nights near 25°C. Pack light clothes and rain gear. Worth having: sun protection. About 24 days see rain.

light clothesrain gearsun protection

Sea temperature near Surat Thani 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 27 km away) is warmest in May at about 31°C and coldest in January near 28°C.

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

26°28°30°32°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan28Warm
Feb28Tropical
Mar29Tropical
Apr30Tropical
May31Tropical
Jun30Tropical
Jul30Tropical
Aug29Tropical
Sep29Tropical
Oct29Tropical
Nov29Tropical
Dec28Warm

UV index in Surat Thani in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 13 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Surat Thani peaks around August 21 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 16 at about 10 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highAug 21UV 13Dec 16UV 10
UV index (midday)Level
Jan10Extreme
Feb12Extreme
Mar13Extreme
Apr13Extreme
May12Extreme
Jun12Extreme
Jul11Extreme
Aug14Extreme
Sep13Extreme
Oct12Extreme
Nov10Extreme
Dec10Very high

Air quality in Surat Thani 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 Surat Thani is worst in April — around 21 µg/m³ PM2.5 (moderate), and holds fairly steady the rest of the year.

Seasonal pattern from CAMS reanalysis, scaled to Surat Thani's WHO annual average of 17 µg/m³.

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateApr 1021 µg/m³Aug 2014 µg/m³
PM2.5 (µg/m³)Level
Jan19Moderate
Feb19Moderate
Mar21Moderate
Apr21Moderate
May17Moderate
Jun16Moderate
Jul17Moderate
Aug14Moderate
Sep15Moderate
Oct15Moderate
Nov15Moderate
Dec15Moderate
Location & terrain

Where is Surat Thani?

Surat Thani sits at 9.1°N, 99.3°E, 10 m above sea level, in Thailand. The nearest listed city is Tha Kham, 12 km away.

Lang SuanKo Pha-nganNakhon Si ThammaratThung SongKo Tao

Topography around Surat Thani

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

Within 3 km, the terrain around Surat Thani has only modest variations in elevation — a maximum elevation change of 35 m around an average of 6 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 308 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,599 m.

The land around Surat Thani is covered by artificial surfaces (45%) and trees (35%) within 3 km, trees (57%) and water (23%) within 16 km, and trees (68%) and water (29%) within 80 km.

3 km
35 m
16 km
308 m
80 km
1,599 m
treesgrasslandcroplandartificial surfacesbare terrainwatermangroves
September weather nearby: Tha Kham 12 km · Ban Na San 38 km · Ko Samui 79 km · Lang Suan 94 km · Ko Pha-ngan 103 km · Nakhon Si Thammarat 105 km · Thung Song 115 km · Ko Tao 119 km

Thailand travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type A / B / C
230 V · 50 Hz
Prices
≈ 31% of US
price level, 2025
GDP per capita
$8,057
2025
Happiness
6.3 / 10
World Happiness, 2025
Homicide rate
4.8
per 100k, 2011
Road deaths
32.2
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Very low
EF EPI 402
Religion
Buddhist 93%Muslim 5%Christian 1%other 1%

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 Surat Thani (9.1401°, 99.3331°, elevation 10 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).