Ko Pha-ngan weather in September

In September, Ko Pha-ngan sees average daytime highs of 28°C and overnight lows near 27°C, with 179 mm of rain across 23.5 wet days and about 12.1 hours of daylight. It is the 6th-warmest and 3rd-wettest month of the year here.

Day-to-day highs hold fairly steady near 28°C through the month. The sky is clear or mostly clear about 6% 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 Ko Pha-ngan's 9th-clearest and 4th-windiest month. For the whole year in context, see Ko Pha-ngan's year-round climate.

Daytime high
28°
6th warmest
Overnight low
27°
6th coldest
Rainfall
179 mm
23.5 wet days
Daylight
12 h 06 min
6:13 AM – 6:16 PM
Cloud cover
84%
9th clearest
Wind
19 km/h
4th windiest
Solar energy
5.17 kWh/m²
Travel score
3.8
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 28°C through the month.

A typical September day in Ko Pha-ngan reaches about 28°C in the afternoon and slips back to 27°C overnight — a 2°C spread between the day's warmth and the night's chill. On most days the high lands between 27°C and 29°C. Set against its neighbours, September runs on par with August and on par with October.

24°26°28°30°32°151015202530
Avg high (°C)Avg low (°C)
12827
22827
32827
42827
52827
62827
72827
82827
92827
102827
112827
122827
132827
142827
152827
162827
172827
182827
192827
202827
212827
222826
232826
242826
252826
262826
272826
282826
292826
302826

How September really feels in Ko Pha-ngan

Once humidity and wind are folded in, September averages 15 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
15
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.

Ko Pha-ngan weather by month

How September compares with the rest of the year at a glance. September is the 6th-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan27° / 26°768.511.56.8
Feb27° / 26°33511.77.3
Mar28° / 27°908.911.96.4
Apr29° / 28°10112.912.25.1
May29° / 27°14822.712.43.7
Jun29° / 27°12420.612.63.8
Jul29° / 27°11420.612.54.0
Aug29° / 27°12419.712.34.1
Sep28° / 27°17923.512.13.8
Oct28° / 26°30425.911.83.9
Nov28° / 26°28220.711.64.6
Dec27° / 26°13312.111.46.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 6% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 8% of September, with mostly cloudy or overcast conditions the remaining 86%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
11288
21288
31288
41288
51288
61288
71288
81288
91288
101288
111288
121288
131387
141387
151387
161486
171585
181585
191585
201684
211684
221684
231783
241783
251783
261783
271783
281882
291882
301882

Chance of precipitation in September

Any precipitation

Ko Pha-ngan gets around 179 mm of rain over 23.5 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 79% and peaks near 84% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%151015202530
Rain chance (%)
171
271
372
472
573
674
775
876
976
1077
1178
1278
1379
1479
1580
1680
1780
1881
1981
2081
2181
2281
2382
2482
2582
2682
2783
2883
2984
3084

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 60% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Oppressive (%)Miserable (%)
15248
25347
35446
45545
55644
65743
75842
85842
95941
106040
116040
126139
136139
146238
156238
166238
176238
186238
196238
206238
216238
226238
236238
246238
256337
266337
276436
286535
296634
306634

Wind in September

Winds average 19 km/h in September.

Across September, daily wind ranges from about 17 km/h on the calmest days to 20 km/h at its breeziest. It stays fairly steady from day to day.

0510152025151015202530
Wind speed (km/h)Feels
119light breeze
219light breeze
319light breeze
419light breeze
519light breeze
619light breeze
720light breeze
820light breeze
920light breeze
1020light breeze
1120light breeze
1220light breeze
1320light breeze
1420light breeze
1520light breeze
1620light breeze
1720light breeze
1820light breeze
1920light breeze
2019light breeze
2119light breeze
2219light breeze
2319light breeze
2419light breeze
2518light breeze
2618light breeze
2718light breeze
2818light breeze
2918light breeze
3017light breeze

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 6:14 AM to 6:11 AM, and sunset from 6:25 PM to 6:07 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.26:146:25
212.26:146:25
312.26:146:24
412.26:146:23
512.26:146:23
612.16:146:22
712.16:136:22
812.16:136:21
912.16:136:20
1012.16:136:20
1112.16:136:19
1212.16:136:18
1312.16:136:18
1412.16:136:17
1512.16:136:16
1612.16:136:16
1712.06:136:15
1812.06:126:15
1912.06:126:14
2012.06:126:13
2112.06:126:13
2212.06:126:12
2312.06:126:11
2412.06:126:11
2512.06:126:10
2612.06:126:09
2712.06:126:09
2811.96:126:08
2911.96:126:08
3011.96:116:07

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.17 kWh/m².

For context, solar energy here swings from a low near 4.55 kWh/m² to a high of 6.44 kWh/m² in April across the year — September's 5.17 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.4Bright
25.4Bright
35.4Bright
45.3Bright
55.3Bright
65.3Bright
75.3Bright
85.3Bright
95.2Bright
105.2Bright
115.2Bright
125.2Bright
135.2Bright
145.1Bright
155.1Bright
165.1Bright
175.1Bright
185.1Bright
195.1Bright
205.1Bright
215.1Bright
225.1Bright
235.0Bright
245.0Bright
255.0Bright
265.0Bright
275.0Bright
285.0Bright
295.0Bright
305.0Bright
Planning a trip in September

Hazard calendar for Ko Pha-ngan

In seasonPeak

In September, Ko Pha-ngan sits inside its pacific typhoon and rainy season season. The full year is below, with each hazard's peak months called out.

Ko Pha-ngan sits in the Pacific typhoon belt; the season peaks July–October.

Ko Pha-ngan's rainy season runs September–November, when most of the year's rain falls.

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

Is September a good time to visit Ko Pha-ngan?

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

3.8
Sightseeing
10th-best month of the year
4.4
Beach & pool
11th-best month of the year

September is a weaker month for outdoor sightseeing in Ko Pha-ngan.

What to pack for Ko Pha-ngan in September

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

In September, Ko Pha-ngan sees daytime highs around 28°C and nights near 27°C. Pack light clothes and rain gear. Worth having: sun protection. About 24 days see rain.

light clothesrain gearsun protection

Sea temperature near Ko Pha-ngan 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 17 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
Jul30Tropical
Aug29Tropical
Sep29Tropical
Oct29Tropical
Nov29Tropical
Dec28Tropical

UV index in Ko Pha-ngan 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 Ko Pha-ngan peaks around August 22 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 18 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 22UV 14Dec 18UV 10
UV index (midday)Level
Jan10Very high
Feb12Extreme
Mar13Extreme
Apr13Extreme
May13Extreme
Jun12Extreme
Jul11Extreme
Aug14Extreme
Sep13Extreme
Oct11Extreme
Nov10Extreme
Dec10Very high

Air quality in Ko Pha-ngan 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 Ko Pha-ngan is worst in January — around 16 µg/m³ PM2.5 (moderate), and holds fairly steady the rest of the year.

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

01020JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodJan 2016 µg/m³Nov 1110 µg/m³
PM2.5 (µg/m³)Level
Jan16Moderate
Feb15Moderate
Mar13Moderate
Apr14Moderate
May13Moderate
Jun14Moderate
Jul15Moderate
Aug12Good
Sep12Good
Oct11Good
Nov10Good
Dec12Moderate
Location & terrain

Where is Ko Pha-ngan?

Ko Pha-ngan sits at 9.8°N, 100.0°E, 0 m above sea level, in Thailand. The nearest listed city is Ko Samui, 27 km away.

Surat ThaniLang SuanTha KhamChumphonBan Na SanNakhon Si Thammarat

Topography around Ko Pha-ngan

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Ko Pha-ngan.

Within 3 km, the terrain around Ko Pha-ngan has large variations in elevation — a maximum elevation change of 613 m around an average of 257 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 618 m; within 80 km, large variations in elevation — a maximum elevation change of 805 m.

The land around Ko Pha-ngan is covered by trees (99%) within 3 km, water (85%) within 16 km, and water (92%) within 80 km.

3 km
613 m
16 km
618 m
80 km
805 m
treeswater
September weather nearby: Ko Samui 27 km · Ko Tao 43 km · Surat Thani 103 km · Lang Suan 106 km · Tha Kham 113 km · Chumphon 124 km · Ban Na San 129 km · Nakhon Si Thammarat 147 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 Ko Pha-ngan (9.7578°, 100.0291°, elevation 0 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).