Ko Tao weather in September

In September, Ko Tao sees average daytime highs of 28°C and overnight lows near 27°C, with 168 mm of rain across 23 wet days and about 12.1 hours of daylight. It is the 7th-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 4% 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 Tao's 9th-clearest and 4th-windiest month. For the whole year in context, see Ko Tao's year-round climate.

Daytime high
28°
7th warmest
Overnight low
27°
6th coldest
Rainfall
168 mm
23 wet days
Daylight
12 h 06 min
6:13 AM – 6:17 PM
Cloud cover
84%
9th clearest
Wind
19 km/h
4th windiest
Solar energy
5.02 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 Tao 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
222827
232827
242826
252826
262826
272826
282826
292826
302826

How September really feels in Ko Tao

Once humidity and wind are folded in, September averages 26 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
26
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 Tao weather by month

How September compares with the rest of the year at a glance. September is the 7th-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan27° / 26°728.211.56.9
Feb28° / 27°304.411.77.4
Mar28° / 27°878.411.96.3
Apr29° / 28°9712.712.25.1
May29° / 28°15022.312.53.7
Jun29° / 27°12720.412.63.8
Jul29° / 27°11520.112.54.0
Aug29° / 27°12119.612.34.2
Sep28° / 27°1682312.13.8
Oct28° / 26°29025.211.84.0
Nov28° / 26°25619.111.54.8
Dec27° / 26°1221111.46.2

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 4% 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 87%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
11090
21090
31189
41189
51189
61189
71090
81189
91189
101189
111189
121189
131189
141189
151387
161387
171387
181387
191486
201486
211486
221486
231486
241486
251585
261585
271585
281585
291585
301585

Chance of precipitation in September

Any precipitation

Ko Tao gets around 168 mm of rain over 23 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 77% and peaks near 83% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%151015202530
Rain chance (%)
169
270
370
471
571
672
773
873
974
1074
1175
1276
1376
1477
1577
1678
1779
1879
1980
2080
2181
2281
2381
2481
2581
2682
2782
2882
2982
3083

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 51% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Oppressive (%)Miserable (%)
14456
24555
34555
44654
54753
64852
74852
84951
94951
105050
115050
125149
135149
145248
155248
165248
175248
185248
195248
205248
215248
225248
235248
245248
255347
265446
275545
285644
295743
305842

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
120light breeze
220light breeze
319light breeze
419light breeze
520light breeze
620light 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
1919light breeze
2019light breeze
2119light breeze
2219light breeze
2319light breeze
2419light breeze
2518light breeze
2618light breeze
2718light breeze
2818light breeze
2917light 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 6:12 AM, and sunset from 6:26 PM to 6:08 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.26:146:26
212.26:146:26
312.26:146:25
412.26:146:24
512.26:146:24
612.16:146:23
712.16:146:22
812.16:146:22
912.16:146:21
1012.16:146:21
1112.16:146:20
1212.16:146:19
1312.16:146:19
1412.16:136:18
1512.16:136:17
1612.16:136:17
1712.06:136:16
1812.06:136:15
1912.06:136:15
2012.06:136:14
2112.06:136:13
2212.06:136:13
2312.06:136:12
2412.06:136:11
2512.06:136:11
2612.06:136:10
2711.96:126:09
2811.96:126:09
2911.96:126:08
3011.96:126:08

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.02 kWh/m².

For context, solar energy here swings from a low near 4.51 kWh/m² to a high of 6.4 kWh/m² in April across the year — September's 5.02 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.2Bright
25.2Bright
35.2Bright
45.2Bright
55.2Bright
65.2Bright
75.1Bright
85.1Bright
95.1Bright
105.1Bright
115.0Bright
125.0Bright
135.0Bright
145.0Bright
155.0Bright
165.0Bright
174.9Bright
184.9Bright
194.9Bright
204.9Bright
214.9Bright
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 Ko Tao

In seasonPeak

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

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

Ko Tao's rainy season runs September–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 Ko Tao?

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
4.5
Beach & pool
11th-best month of the year

September is a weaker month for outdoor sightseeing in Ko Tao.

What to pack for Ko Tao in September

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

In September, Ko Tao sees daytime highs around 28°C and nights near 27°C. Pack light clothes and rain gear. Worth having: sun protection. About 23 days see rain.

light clothesrain gearsun protection

Sea temperature near Ko Tao 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 offshore 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 Ko Tao 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 Tao peaks around August 20 at about 14 (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 14Dec 20UV 9
UV index (midday)Level
Jan10Very high
Feb12Extreme
Mar13Extreme
Apr13Extreme
May12Extreme
Jun12Extreme
Jul12Extreme
Aug14Extreme
Sep13Extreme
Oct11Extreme
Nov10Extreme
Dec9Very high

Air quality in Ko Tao 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 Tao 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 Tao?

Ko Tao sits at 10.1°N, 99.8°E, 0 m above sea level, in Thailand. The nearest listed city is Ko Pha-ngan, 43 km away.

Surat ThaniTha KhamBang SaphanRanong

Topography around Ko Tao

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

Within 3 km, the terrain around Ko Tao has significant variations in elevation — a maximum elevation change of 368 m around an average of 60 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 368 m; within 80 km, large variations in elevation — a maximum elevation change of 621 m.

The land around Ko Tao is covered by water (49%) and trees (47%) within 3 km, water (98%) within 16 km, and water (95%) within 80 km.

3 km
368 m
16 km
368 m
80 km
621 m
treesartificial surfaceswater
September weather nearby: Ko Pha-ngan 43 km · Ko Samui 63 km · Lang Suan 85 km · Chumphon 85 km · Surat Thani 119 km · Tha Kham 128 km · Bang Saphan 130 km · Ranong 132 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 Tao (10.0917°, 99.8377°, 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).