Ko Samui weather in October
In October, Ko Samui sees average daytime highs of 28°C and overnight lows near 26°C, with 286 mm of rain across 26 wet days and about 11.8 hours of daylight. It is the 8th-warmest and 2nd-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 9% of the time in October, and the air most often feels oppressive.
Daylight stretches from about 11 h 54 min at the start of October to 11 h 42 min by month's end. Set against the rest of the year, October is Ko Samui's 8th-clearest and 11th-windiest month. For the whole year in context, see Ko Samui's year-round climate.
- Daytime high
- 28°
- 8th warmest
- Overnight low
- 26°
- 4th coldest
- Rainfall
- 286 mm
- 26 wet days
- Daylight
- 11 h 48 min
- 6:12 AM – 5:59 PM
- Cloud cover
- 79%
- 8th clearest
- Wind
- 14 km/h
- 11th windiest
- Solar energy
- 4.7 kWh/m²
- Travel score
- 3.9
- out of 10
Ko Samui is city in Surat Thani province, Thailand.
- Density
- 219/km²
- people per km²
- Founded
- 1956
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Temperature in October
Day-to-day highs hold fairly steady near 28°C through the month.
A typical October day in Ko Samui reaches about 28°C in the afternoon and slips back to 26°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, October runs on par with September and on par with November.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 | 28 |
| Avg low (°C) | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| 1 | 28 | 26 |
| 2 | 28 | 26 |
| 3 | 28 | 26 |
| 4 | 28 | 26 |
| 5 | 28 | 26 |
| 6 | 28 | 26 |
| 7 | 28 | 26 |
| 8 | 28 | 26 |
| 9 | 28 | 26 |
| 10 | 28 | 26 |
| 11 | 28 | 26 |
| 12 | 28 | 26 |
| 13 | 28 | 26 |
| 14 | 28 | 26 |
| 15 | 28 | 26 |
| 16 | 28 | 26 |
| 17 | 28 | 26 |
| 18 | 28 | 26 |
| 19 | 28 | 26 |
| 20 | 28 | 26 |
| 21 | 28 | 26 |
| 22 | 28 | 26 |
| 23 | 28 | 26 |
| 24 | 28 | 26 |
| 25 | 28 | 26 |
| 26 | 28 | 26 |
| 27 | 28 | 26 |
| 28 | 28 | 26 |
| 29 | 28 | 26 |
| 30 | 28 | 26 |
| 31 | 28 | 26 |
How October really feels in Ko Samui
Once humidity and wind are folded in, October averages 0 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.
October sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.
Ko Samui weather by month
How October compares with the rest of the year at a glance. October is the 8th-warmest and 2nd-wettest month here — the current month is highlighted below.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 27° / 26° | 76 | 9.4 | 11.5 | 6.7 |
| Feb | 27° / 26° | 35 | 5.3 | 11.7 | 7.3 |
| Mar | 28° / 27° | 88 | 8.4 | 11.9 | 6.4 |
| Apr | 29° / 28° | 95 | 11.7 | 12.2 | 5.3 |
| May | 29° / 27° | 116 | 21.2 | 12.4 | 3.8 |
| Jun | 29° / 27° | 89 | 18.8 | 12.5 | 3.9 |
| Jul | 29° / 27° | 84 | 18.4 | 12.5 | 4.2 |
| Aug | 29° / 27° | 91 | 18 | 12.3 | 4.3 |
| Sep | 28° / 27° | 140 | 22.8 | 12.1 | 3.9 |
| Oct | 28° / 26° | 286 | 26 | 11.8 | 3.9 |
| Nov | 28° / 26° | 289 | 20.9 | 11.6 | 4.6 |
| Dec | 27° / 26° | 145 | 13.2 | 11.5 | 5.9 |
Cloud cover in October
The sky is clear or mostly clear about 9% of the time in October.
Beyond those clear spells, partly cloudy skies cover about 11% of October, with mostly cloudy or overcast conditions the remaining 79%. Skies tend to open up as the month goes on.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 17 | 17 | 17 | 18 | 18 | 18 | 18 | 19 | 19 | 19 | 19 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 21 | 22 | 22 | 22 | 22 | 24 | 24 | 24 | 24 | 25 | 26 | 26 |
| Cloudier (%) | 83 | 83 | 83 | 82 | 82 | 82 | 82 | 81 | 81 | 81 | 81 | 80 | 80 | 80 | 80 | 80 | 80 | 80 | 80 | 79 | 78 | 78 | 78 | 78 | 76 | 76 | 76 | 76 | 75 | 74 | 74 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 17 | 83 |
| 2 | 17 | 83 |
| 3 | 17 | 83 |
| 4 | 18 | 82 |
| 5 | 18 | 82 |
| 6 | 18 | 82 |
| 7 | 18 | 82 |
| 8 | 19 | 81 |
| 9 | 19 | 81 |
| 10 | 19 | 81 |
| 11 | 19 | 81 |
| 12 | 20 | 80 |
| 13 | 20 | 80 |
| 14 | 20 | 80 |
| 15 | 20 | 80 |
| 16 | 20 | 80 |
| 17 | 20 | 80 |
| 18 | 20 | 80 |
| 19 | 20 | 80 |
| 20 | 21 | 79 |
| 21 | 22 | 78 |
| 22 | 22 | 78 |
| 23 | 22 | 78 |
| 24 | 22 | 78 |
| 25 | 24 | 76 |
| 26 | 24 | 76 |
| 27 | 24 | 76 |
| 28 | 24 | 76 |
| 29 | 25 | 75 |
| 30 | 26 | 74 |
| 31 | 26 | 74 |
Chance of precipitation in October
Ko Samui gets around 286 mm of rain over 26 wet days in October. The line is the day-by-day chance of measurable precipitation.
Day to day, the chance of measurable rain averages around 83% and peaks near 85% on the wettest days.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain chance (%) | 84 | 84 | 85 | 85 | 85 | 85 | 85 | 85 | 85 | 85 | 85 | 84 | 84 | 84 | 84 | 84 | 83 | 83 | 83 | 83 | 83 | 83 | 82 | 82 | 82 | 82 | 81 | 81 | 80 | 80 | 79 |
| Rain chance (%) | |
|---|---|
| 1 | 84 |
| 2 | 84 |
| 3 | 85 |
| 4 | 85 |
| 5 | 85 |
| 6 | 85 |
| 7 | 85 |
| 8 | 85 |
| 9 | 85 |
| 10 | 85 |
| 11 | 85 |
| 12 | 84 |
| 13 | 84 |
| 14 | 84 |
| 15 | 84 |
| 16 | 84 |
| 17 | 83 |
| 18 | 83 |
| 19 | 83 |
| 20 | 83 |
| 21 | 83 |
| 22 | 83 |
| 23 | 82 |
| 24 | 82 |
| 25 | 82 |
| 26 | 82 |
| 27 | 81 |
| 28 | 81 |
| 29 | 80 |
| 30 | 80 |
| 31 | 79 |
Humidity in October
Most of October feels oppressive — the stacked bands show each day's mix of comfort levels, read off the dew point.
By dew point, October lands in the oppressive band about 75% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Muggy (%) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| Oppressive (%) | 76 | 77 | 77 | 78 | 78 | 78 | 78 | 78 | 78 | 77 | 77 | 76 | 76 | 75 | 75 | 74 | 73 | 73 | 71 | 71 | 71 | 71 | 71 | 72 | 73 | 74 | 75 | 76 | 77 | 78 | 78 |
| Miserable (%) | 24 | 23 | 23 | 22 | 22 | 22 | 22 | 22 | 22 | 23 | 23 | 24 | 24 | 25 | 25 | 26 | 27 | 27 | 28 | 28 | 28 | 28 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 21 |
| Muggy (%) | Oppressive (%) | Miserable (%) | |
|---|---|---|---|
| 1 | 0 | 76 | 24 |
| 2 | 0 | 77 | 23 |
| 3 | 0 | 77 | 23 |
| 4 | 0 | 78 | 22 |
| 5 | 0 | 78 | 22 |
| 6 | 0 | 78 | 22 |
| 7 | 0 | 78 | 22 |
| 8 | 0 | 78 | 22 |
| 9 | 0 | 78 | 22 |
| 10 | 0 | 77 | 23 |
| 11 | 0 | 77 | 23 |
| 12 | 0 | 76 | 24 |
| 13 | 0 | 76 | 24 |
| 14 | 0 | 75 | 25 |
| 15 | 0 | 75 | 25 |
| 16 | 0 | 74 | 26 |
| 17 | 0 | 73 | 27 |
| 18 | 0 | 73 | 27 |
| 19 | 1 | 71 | 28 |
| 20 | 1 | 71 | 28 |
| 21 | 1 | 71 | 28 |
| 22 | 1 | 71 | 28 |
| 23 | 1 | 71 | 28 |
| 24 | 1 | 72 | 27 |
| 25 | 1 | 73 | 26 |
| 26 | 1 | 74 | 25 |
| 27 | 1 | 75 | 24 |
| 28 | 1 | 76 | 23 |
| 29 | 1 | 77 | 22 |
| 30 | 1 | 78 | 21 |
| 31 | 1 | 78 | 21 |
Wind in October
Winds average 14 km/h in October.
Across October, daily wind ranges from about 14 km/h on the calmest days to 16 km/h at its breeziest. It stays fairly steady from day to day.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (km/h) | 16 | 15 | 15 | 15 | 15 | 15 | 15 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 14 | 15 | 15 | 15 | 15 | 15 | 15 | 15 |
| Feels | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze |
| Wind speed (km/h) | Feels | |
|---|---|---|
| 1 | 16 | light breeze |
| 2 | 15 | light breeze |
| 3 | 15 | light breeze |
| 4 | 15 | light breeze |
| 5 | 15 | light breeze |
| 6 | 15 | light breeze |
| 7 | 15 | light breeze |
| 8 | 14 | light breeze |
| 9 | 14 | light breeze |
| 10 | 14 | light breeze |
| 11 | 14 | light breeze |
| 12 | 14 | light breeze |
| 13 | 14 | light breeze |
| 14 | 14 | light breeze |
| 15 | 14 | light breeze |
| 16 | 14 | light breeze |
| 17 | 14 | light breeze |
| 18 | 14 | light breeze |
| 19 | 14 | light breeze |
| 20 | 14 | light breeze |
| 21 | 14 | light breeze |
| 22 | 14 | light breeze |
| 23 | 14 | light breeze |
| 24 | 14 | light breeze |
| 25 | 15 | light breeze |
| 26 | 15 | light breeze |
| 27 | 15 | light breeze |
| 28 | 15 | light breeze |
| 29 | 15 | light breeze |
| 30 | 15 | light breeze |
| 31 | 15 | light breeze |
Sunrise & sunset in October
Daylight runs from about 11 h 54 min at the start of October to 11 h 42 min by month's end. The lit band spans sunrise to sunset each day.
Days shrink by about 12 minutes over October. Sunrise moves from 6:12 AM to 6:14 AM, and sunset from 6:07 PM to 5:54 PM.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 11.9 | 11.9 | 11.9 | 11.9 | 11.9 | 11.9 | 11.9 | 11.9 | 11.8 | 11.8 | 11.8 | 11.8 | 11.8 | 11.8 | 11.8 | 11.8 | 11.8 | 11.8 | 11.8 | 11.8 | 11.7 | 11.7 | 11.7 | 11.7 | 11.7 | 11.7 | 11.7 | 11.7 | 11.7 | 11.7 | 11.7 |
| Sunrise (AM) | 6:12 | 6:12 | 6:12 | 6:12 | 6:12 | 6:12 | 6:12 | 6:12 | 6:12 | 6:12 | 6:12 | 6:12 | 6:12 | 6:12 | 6:12 | 6:12 | 6:12 | 6:12 | 6:12 | 6:12 | 6:12 | 6:12 | 6:12 | 6:13 | 6:13 | 6:13 | 6:13 | 6:13 | 6:13 | 6:14 | 6:14 |
| Sunset (PM) | 6:07 | 6:06 | 6:06 | 6:05 | 6:04 | 6:04 | 6:03 | 6:03 | 6:02 | 6:02 | 6:01 | 6:01 | 6:00 | 6:00 | 5:59 | 5:59 | 5:58 | 5:58 | 5:58 | 5:57 | 5:57 | 5:56 | 5:56 | 5:56 | 5:55 | 5:55 | 5:55 | 5:54 | 5:54 | 5:54 | 5:54 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 11.9 | 6:12 | 6:07 |
| 2 | 11.9 | 6:12 | 6:06 |
| 3 | 11.9 | 6:12 | 6:06 |
| 4 | 11.9 | 6:12 | 6:05 |
| 5 | 11.9 | 6:12 | 6:04 |
| 6 | 11.9 | 6:12 | 6:04 |
| 7 | 11.9 | 6:12 | 6:03 |
| 8 | 11.9 | 6:12 | 6:03 |
| 9 | 11.8 | 6:12 | 6:02 |
| 10 | 11.8 | 6:12 | 6:02 |
| 11 | 11.8 | 6:12 | 6:01 |
| 12 | 11.8 | 6:12 | 6:01 |
| 13 | 11.8 | 6:12 | 6:00 |
| 14 | 11.8 | 6:12 | 6:00 |
| 15 | 11.8 | 6:12 | 5:59 |
| 16 | 11.8 | 6:12 | 5:59 |
| 17 | 11.8 | 6:12 | 5:58 |
| 18 | 11.8 | 6:12 | 5:58 |
| 19 | 11.8 | 6:12 | 5:58 |
| 20 | 11.8 | 6:12 | 5:57 |
| 21 | 11.7 | 6:12 | 5:57 |
| 22 | 11.7 | 6:12 | 5:56 |
| 23 | 11.7 | 6:12 | 5:56 |
| 24 | 11.7 | 6:13 | 5:56 |
| 25 | 11.7 | 6:13 | 5:55 |
| 26 | 11.7 | 6:13 | 5:55 |
| 27 | 11.7 | 6:13 | 5:55 |
| 28 | 11.7 | 6:13 | 5:54 |
| 29 | 11.7 | 6:13 | 5:54 |
| 30 | 11.7 | 6:14 | 5:54 |
| 31 | 11.7 | 6:14 | 5:54 |
Solar energy in October
Average shortwave solar energy reaching the ground each day in October, about 4.7 kWh/m².
For context, solar energy here swings from a low near 4.49 kWh/m² to a high of 6.44 kWh/m² in April across the year — October's 4.7 kWh/m² sits near the bottom.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 5.0 | 5.0 | 4.9 | 4.9 | 4.9 | 4.9 | 4.9 | 4.9 | 4.8 | 4.8 | 4.8 | 4.8 | 4.8 | 4.8 | 4.8 | 4.7 | 4.7 | 4.7 | 4.7 | 4.6 | 4.6 | 4.6 | 4.6 | 4.5 | 4.5 | 4.5 | 4.5 | 4.5 | 4.5 | 4.5 | 4.5 |
| Level | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| 1 | 5.0 | Bright |
| 2 | 5.0 | Bright |
| 3 | 4.9 | Bright |
| 4 | 4.9 | Bright |
| 5 | 4.9 | Bright |
| 6 | 4.9 | Bright |
| 7 | 4.9 | Bright |
| 8 | 4.9 | Bright |
| 9 | 4.8 | Bright |
| 10 | 4.8 | Bright |
| 11 | 4.8 | Bright |
| 12 | 4.8 | Bright |
| 13 | 4.8 | Bright |
| 14 | 4.8 | Bright |
| 15 | 4.8 | Bright |
| 16 | 4.7 | Bright |
| 17 | 4.7 | Bright |
| 18 | 4.7 | Bright |
| 19 | 4.7 | Bright |
| 20 | 4.6 | Bright |
| 21 | 4.6 | Bright |
| 22 | 4.6 | Bright |
| 23 | 4.6 | Bright |
| 24 | 4.5 | Bright |
| 25 | 4.5 | Bright |
| 26 | 4.5 | Bright |
| 27 | 4.5 | Bright |
| 28 | 4.5 | Bright |
| 29 | 4.5 | Bright |
| 30 | 4.5 | Bright |
| 31 | 4.5 | Bright |
Hazard calendar for Ko Samui
In October, Ko Samui sits inside its cyclone and rainy season season. The full year is below, with each hazard's peak months called out.
Ko Samui sits in the North Indian Ocean cyclone zone; the season peaks May and October–November.
Ko Samui's rainy season runs September–December, when most of the year's rain falls.
Is October a good time to visit Ko Samui?
Our two travel scores rate October for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).
October is a weaker month for outdoor sightseeing in Ko Samui.
What to pack for Ko Samui in October
From October's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In October, Ko Samui sees daytime highs around 28°C and nights near 26°C. Pack light clothes and rain gear. Worth having: sun protection. About 26 days see rain.
Sea temperature near Ko Samui in October
The nearest coast averages about 29°C in October — 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 28 | 28 | 29 | 30 | 30 | 30 | 30 | 29 | 29 | 29 | 29 | 28 |
| Comfort | Warm | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Warm |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 28 | Warm |
| Feb | 28 | Tropical |
| Mar | 29 | Tropical |
| Apr | 30 | Tropical |
| May | 30 | Tropical |
| Jun | 30 | Tropical |
| Jul | 30 | Tropical |
| Aug | 29 | Tropical |
| Sep | 29 | Tropical |
| Oct | 29 | Tropical |
| Nov | 29 | Tropical |
| Dec | 28 | Warm |
UV index in Ko Samui in October
Clear-sky midday UV in October 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 Ko Samui 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 10 | 12 | 13 | 13 | 13 | 12 | 11 | 14 | 13 | 11 | 10 | 10 |
| Level | Very high | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Very high |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 10 | Very high |
| Feb | 12 | Extreme |
| Mar | 13 | Extreme |
| Apr | 13 | Extreme |
| May | 13 | Extreme |
| Jun | 12 | Extreme |
| Jul | 11 | Extreme |
| Aug | 14 | Extreme |
| Sep | 13 | Extreme |
| Oct | 11 | Extreme |
| Nov | 10 | Extreme |
| Dec | 10 | Very high |
Air quality in Ko Samui in October
Average fine-particle pollution (PM2.5) through the year — so you can see where October falls, not just the annual average.
Air quality in Ko Samui 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).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 16 | 15 | 13 | 14 | 13 | 14 | 15 | 12 | 12 | 11 | 10 | 12 |
| Level | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Good | Good | Good | Good | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 16 | Moderate |
| Feb | 15 | Moderate |
| Mar | 13 | Moderate |
| Apr | 14 | Moderate |
| May | 13 | Moderate |
| Jun | 14 | Moderate |
| Jul | 15 | Moderate |
| Aug | 12 | Good |
| Sep | 12 | Good |
| Oct | 11 | Good |
| Nov | 10 | Good |
| Dec | 12 | Moderate |
Where is Ko Samui?
Ko Samui sits at 9.5°N, 99.9°E, 8 m above sea level, in Thailand. The nearest listed city is Ko Pha-ngan, 27 km away.
Topography around Ko Samui
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Ko Samui.
Within 3 km, the terrain around Ko Samui has significant variations in elevation — a maximum elevation change of 476 m around an average of 56 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 629 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,358 m.
The land around Ko Samui is covered by trees (51%) and water (42%) within 3 km, water (72%) and trees (24%) within 16 km, and water (82%) within 80 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
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 Samui (9.5357°, 99.9357°, elevation 8 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).