Lang Suan weather in September

In September, Lang Suan sees average daytime highs of 30°C and overnight lows near 24°C, with 302 mm of rain across 26.6 wet days and about 12.1 hours of daylight. It is the 8th-warmest and 2nd-wettest month of the year here.

Day-to-day highs hold fairly steady near 30°C through the month. The sky is clear or mostly clear about 2% of the time in September, and the air most often feels oppressive.

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 Lang Suan's 10th-clearest and 5th-windiest month. For the whole year in context, see Lang Suan's year-round climate.

Daytime high
30°
8th warmest
Overnight low
24°
7th coldest
Rainfall
302 mm
26.6 wet days
Daylight
12 h 06 min
6:16 AM – 6:20 PM
Cloud cover
87%
10th clearest
Wind
9 km/h
5th windiest
Solar energy
4.75 kWh/m²
Travel score
2.8
out of 10

Lang Suan is town in Lang Suan district, Chumphon province, Thailand.

Founded
1940

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 30°C through the month.

A typical September day in Lang Suan reaches about 30°C in the afternoon and slips back to 24°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 28°C and 32°C. Set against its neighbours, September runs on par with August and on par with October.

20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
13124
23024
33024
43024
53024
63024
73024
83024
93024
103024
113024
123024
133024
143024
153024
163024
173024
183024
193024
203024
213024
223024
233024
243024
253024
263024
273024
283024
293024
303024

How September really feels in Lang Suan

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.

Lang Suan weather by month

How September compares with the rest of the year at a glance. September is the 8th-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan29° / 22°6810.411.55.3
Feb31° / 22°387.811.75.0
Mar32° / 23°9311.511.93.9
Apr33° / 24°11816.112.22.9
May32° / 25°20124.312.42.4
Jun31° / 25°18821.712.62.9
Jul31° / 24°20623.312.53.0
Aug31° / 24°22524.712.32.9
Sep30° / 24°30226.612.12.8
Oct30° / 23°32627.411.82.9
Nov29° / 23°21421.911.53.7
Dec29° / 22°10313.811.45.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 2% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 5% of September, with mostly cloudy or overcast conditions the remaining 93%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1793
2793
3694
4595
5595
6595
7595
8595
9595
10595
11694
12694
13694
14694
15793
16793
17793
18793
19793
20892
21892
22892
23892
24892
25892
26892
27793
28793
29793
30793

Chance of precipitation in September

Any precipitation

Lang Suan gets around 302 mm of rain over 26.6 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 89% and peaks near 92% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%100%151015202530
Rain chance (%)
185
285
385
486
586
686
786
887
987
1087
1188
1288
1388
1488
1589
1689
1789
1890
1990
2090
2191
2291
2391
2491
2591
2691
2792
2892
2992
3092

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the oppressive band about 58% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Oppressive (%)Miserable (%)
15842
25842
35842
45941
55941
65941
76040
86040
96040
106139
116139
126139
136040
146040
156040
165941
175941
185842
195842
205743
215743
225743
235644
245644
255644
265644
275644
285644
295644
305644

Wind in September

Winds average 9 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
149calm
159calm
169calm
179calm
189calm
199calm
209calm
219calm
229calm
239calm
249calm
259calm
268calm
278calm
288calm
298calm
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 6:18 AM to 6:15 AM, and sunset from 6:29 PM to 6:11 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.26:186:29
212.26:186:29
312.26:176:28
412.26:176:27
512.26:176:27
612.16:176:26
712.16:176:25
812.16:176:25
912.16:176:24
1012.16:176:24
1112.16:176:23
1212.16:176:22
1312.16:176:22
1412.16:176:21
1512.16:166:20
1612.16:166:20
1712.06:166:19
1812.06:166:18
1912.06:166:18
2012.06:166:17
2112.06:166:16
2212.06:166:16
2312.06:166:15
2412.06:166:14
2512.06:166:14
2612.06:166:13
2712.06:156:13
2811.96:156:12
2911.96:156:11
3011.96:156:11

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.75 kWh/m².

For context, solar energy here swings from a low near 4.38 kWh/m² to a high of 6.29 kWh/m² in March across the year — September's 4.75 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.9Bright
24.9Bright
34.9Bright
44.9Bright
54.8Bright
64.8Bright
74.8Bright
84.8Bright
94.8Bright
104.8Bright
114.8Bright
124.7Bright
134.7Bright
144.7Bright
154.7Bright
164.7Bright
174.7Bright
184.7Bright
194.7Bright
204.7Bright
214.7Bright
224.7Bright
234.6Bright
244.6Bright
254.6Bright
264.6Bright
274.6Bright
284.6Bright
294.6Bright
304.6Bright
Planning a trip in September

Hazard calendar for Lang Suan

In seasonPeak

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

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

Lang Suan's rainy season runs May–November, 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 Lang Suan?

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

2.8
Sightseeing
11th-best month of the year
3.9
Beach & pool
12th-best month of the year

September is a weaker month for outdoor sightseeing in Lang Suan.

What to pack for Lang Suan in September

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

In September, Lang Suan sees daytime highs around 30°C and nights near 24°C. Pack light clothes and rain gear. Worth having: sun protection. About 27 days see rain.

light clothesrain gearsun protection

Sea temperature near Lang Suan 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 33 km away) is warmest in May at about 30°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
May30Tropical
Jun30Tropical
Jul29Tropical
Aug29Tropical
Sep29Tropical
Oct29Tropical
Nov29Tropical
Dec28Warm

UV index in Lang Suan 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 Lang Suan peaks around August 20 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 at about 9 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highAug 20UV 13Dec 20UV 9
UV index (midday)Level
Jan10Very high
Feb12Extreme
Mar13Extreme
Apr13Extreme
May12Extreme
Jun12Extreme
Jul12Extreme
Aug14Extreme
Sep13Extreme
Oct11Extreme
Nov10Very high
Dec9Very high

Air quality in Lang Suan 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 Lang Suan is worst in January — around 19 µg/m³ PM2.5 (moderate), and holds fairly steady the rest of the year.

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateJan 2318 µg/m³Oct 1613 µg/m³
PM2.5 (µg/m³)Level
Jan19Moderate
Feb18Moderate
Mar18Moderate
Apr18Moderate
May15Moderate
Jun14Moderate
Jul15Moderate
Aug13Moderate
Sep13Moderate
Oct13Moderate
Nov13Moderate
Dec14Moderate
Location & terrain

Where is Lang Suan?

Lang Suan sits at 9.9°N, 99.1°E, 11 m above sea level, in Thailand. The nearest listed city is Ranong, 49 km away.

Surat ThaniTha KhamKo SamuiKo Pha-ngan

Topography around Lang Suan

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

Within 3 km, the terrain around Lang Suan has only modest variations in elevation — a maximum elevation change of 131 m around an average of 13 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 780 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,296 m.

The land around Lang Suan is covered by trees (78%) within 3 km, trees (74%) within 16 km, and trees (50%) and water (47%) within 80 km.

3 km
131 m
16 km
780 m
80 km
1,296 m
treesgrasslandcroplandartificial surfacesbare terrainwatermangroves
September weather nearby: Ranong 49 km · Kawthaung 58 km · Chumphon 62 km · Ko Tao 85 km · Surat Thani 94 km · Tha Kham 94 km · Ko Samui 104 km · Ko Pha-ngan 106 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 Lang Suan (9.9456°, 99.0785°, elevation 11 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).