10-day forecast — Koh Samui
Refreshed hourly
Thu · Today · 12 Nov
Showers
80°
78°
1.50 in
Wind13 mph E
Gusts22 mph
UV index10 – Very high
Precip chance91%
Sunrise6:12 AM
Sunset5:55 PM
Fri · Tomorrow · 13 Nov
Showers
80°
77°
2.47 in
Wind10 mph SE
Gusts16 mph
UV index8 – Very high
Precip chance92%
Sunrise6:13 AM
Sunset5:55 PM
Saturday · 14 Nov
Showers
83°
78°
0.28 in
Wind8 mph SE
Gusts16 mph
UV index8 – High
Precip chance85%
Sunrise6:13 AM
Sunset5:55 PM
Sunday · 15 Nov
Showers
83°
79°
0.17 in
Wind6 mph SE
Gusts11 mph
UV index10 – Very high
Precip chance80%
Sunrise6:13 AM
Sunset5:55 PM
Monday · 16 Nov
Showers
84°
79°
0.11 in
Wind5 mph S
Gusts15 mph
UV index6 – High
Precip chance73%
Sunrise6:14 AM
Sunset5:55 PM
Tuesday · 17 Nov
Showers
84°
79°
0.03 in
Wind9 mph SE
Gusts15 mph
UV index7 – High
Precip chance55%
Sunrise6:14 AM
Sunset5:55 PM
Wednesday · 18 Nov
Showers
83°
80°
0.16 in
Wind9 mph E
Gusts21 mph
UV index6 – High
Precip chance75%
Sunrise6:14 AM
Sunset5:55 PM
Thursday · 19 Nov
Showers
82°
79°
0.48 in
Wind13 mph E
Gusts25 mph
UV index6 – High
Precip chance87%
Sunrise6:15 AM
Sunset5:55 PM
Friday · 20 Nov
Showers
83°
78°
0.63 in
Wind9 mph E
Gusts20 mph
UV index6 – High
Precip chance87%
Sunrise6:15 AM
Sunset5:55 PM
Saturday · 21 Nov
Showers
82°
78°
0.31 in
Wind10 mph SE
Gusts21 mph
UV index6 – High
Precip chance84%
Sunrise6:16 AM
Sunset5:55 PM
Sunday · 22 Nov
Showers
80°
78°
0.92 in
Wind10 mph E
Gusts20 mph
UV index6 – High
Precip chance91%
Sunrise6:16 AM
Sunset5:55 PM
Monday · 23 Nov
Showers
80°
77°
0.48 in
Wind7 mph E
Gusts17 mph
UV index6 – High
Precip chance89%
Sunrise6:17 AM
Sunset5:55 PM
Tuesday · 24 Nov
Showers
82°
78°
0.13 in
Wind5 mph SE
Gusts15 mph
UV index6 – High
Precip chance74%
Sunrise6:17 AM
Sunset5:55 PM
Wednesday · 25 Nov
Showers
82°
79°
0.09 in
Wind3 mph SE
Gusts12 mph
UV index6 – High
Precip chance75%
Sunrise6:17 AM
Sunset5:55 PM
About Koh Samui
CountryThailand
RegionGulf Islands
ContinentAsia
Time zoneAsia/Bangkok (+07:00)
Latitude9.5120°
Longitude100.0140°
Air QualityGood (AQI 39)
Details & indices
Wind
9 mph E
Gusts 17 mph
Humidity
91%
Dew point 76°
Pressure
29.88 inHg
Falling
UV index
10 — Very high
High today
Air Quality
Good
AQI 39 · US EPA
Visibility
6 mi
Clear view
Sun & moon
Sunrise6:12 AM
Sunset5:55 PM
Length of day11h 43m
Moonrise8:50 AM
Moonset8:34 PM
Moon phase🌔 Waxing Crescent
Local time9:13 PM (+07:00)
Koh Samui climate in September
8-year averages · when to visitBest months: January–December · September: Good
| August | September | October | |
|---|---|---|---|
| Average temperature | ▼ 79°F | 77°F | ▼ 75°F |
| Typical high | ▼ 84°F | 81°F | ▼ 79°F |
| Typical low | → 73°F | 73°F | ▼ 72°F |
| Water temperature | ▼ 88°F | 86°F | ▲ 87°F |
| Precipitation | ▲ 3.6 in | 5.2 in | ▲ 8.9 in |
| Wet days | ▲ 19 d | 21 d | ▲ 28 d |
| Humidity | ▼ 79% | 78% | ▲ 83% |
| Sunshine per day | ▼ 9.4 h | 8.9 h | ▼ 8.8 h |
| Cloud cover | ▲ 24% | 27% | ▼ 26% |
| Midday UV | → 12 | 12 | ▼ 11 |
| Daylight | 12:26 | 12:11 | 11:55 |
| Our take | Good | Good | Good |
September temperatures day by day daily mean + smoothed trend · °F
September precipitation day by day in
September UV day by day clear-sky midday value
Figures are averaged over 8 years of ERA5 reanalysis; sea temps come from ocean reanalysis, and UV is derived from solar elevation.
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NBM + global weather models
Updated: 9:13 PM
Koh Samui, Thailand · 9.51°N, 100.01°E · Asia/Bangkok · Forecast computed for these exact coordinates