Annual mean 29°C · wettest around November · prevailing wind SE
Warmest
32.4 °C
Coldest
28.6 °C
Wettest
81%
Windiest
4.0 m/s
Prevailing
SE
3.0 m/s average
When this place is good five ratings · thirty-six ten-day sections · click a cell to read it
never good
never good
never good
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Every reading
bars actual · line feels-like, °Cchance of rain, %wind speed, m/ssky covered, %
The average temperature in Ko Samui over the whole year is 29°C. May is the hottest month, with highs of about 32°C; December is the coldest, with lows of about 26°C. The rainy (wet) season in Ko Samui runs from October to December, peaking in November with a 76% chance of rain on a given day. The dry season is June to September; August is the driest month, at 46%. Winds in Ko Samui are highest in February, averaging 2.9 m/s (10 km/h), and lightest in October, at 1.4 m/s (5 km/h). The prevailing wind is from the SE. The clearest skies in Ko Samui come in March, when the sky is typically 53% covered; November is the cloudiest month, at 60%.
Month by month Ko Samui climate by month: average temperatures year round · click a month to read it
Month
High
Low
Feels like
Chance of rain
Cloud
Wind
Being outside
Sun
Walking
January
29°C
26°C
32°C
57%
57%
2.5 m/s
3
55
0
February
29°C
27°C
32°C
61%
55%
2.9 m/s
3
56
0
March
30°C
27°C
34°C
56%
53%
2.4 m/s
0
38
0
April
31°C
28°C
36°C
62%
54%
1.9 m/s
0
11
0
May
32°C
28°C
37°C
63%
56%
1.6 m/s
0
5
0
June
32°C
28°C
37°C
56%
57%
1.6 m/s
0
9
0
July
32°C
27°C
36°C
53%
58%
1.6 m/s
0
13
0
August
32°C
27°C
36°C
46%
57%
1.6 m/s
0
15
0
September
31°C
27°C
35°C
47%
58%
1.7 m/s
0
21
0
October
30°C
26°C
35°C
62%
58%
1.4 m/s
0
20
0
November
29°C
26°C
34°C
76%
60%
1.6 m/s
1
33
0
December
29°C
26°C
33°C
67%
58%
2.2 m/s
4
49
0
High and low are the warmest and coolest of four readings a day — midnight, 6am, noon and 6pm — so a true overnight low can sit a degree or two under them. Chance of rain, cloud and wind are the day’s average; feels-like and the three ratings (each out of 100: Good from 55, Ideal from 80) are read at midday.
Seasons, and the year in short Ko Samui weather by season
Year round, Ko Samui has days of about 29°C at their warmest in December, its coolest month, and 32°C in May, its warmest; the coolest hours of the day run from 26°C to 28°C through the year, and the average temperature over the year is 29°C around the clock. Rain is most likely around November and least likely around August. Every figure here is a decade of observations blended into one representative year, so it reads as what this date is usually like, not a forecast for one particular day.
Ko Samui weather in winterDecember to February
High 29°CLow 26°CRain 61%
Winter in Ko Samui has typical daily highs of about 29°C and lows of about 26°C, with a 61% chance of rain on a given day.
Ko Samui weather in springMarch to May
High 31°CLow 28°CRain 60%
Spring in Ko Samui has typical daily highs of about 31°C and lows of about 28°C, with a 60% chance of rain on a given day.
Ko Samui weather in summerJune to August
High 32°CLow 27°CRain 52%
Summer in Ko Samui has typical daily highs of about 32°C and lows of about 27°C, with a 52% chance of rain on a given day.
Ko Samui weather in autumnSeptember to November
High 30°CLow 27°CRain 62%
Autumn in Ko Samui has typical daily highs of about 30°C and lows of about 27°C, with a 62% chance of rain on a given day.
When is the rainy season in Ko Samui?
The rainy (wet) season in Ko Samui runs from October to December, peaking in November with a 76% chance of rain on a given day. The dry season is June to September; August is the driest month, at 46%.
What time of year is Ko Samui windiest?
Winds in Ko Samui are highest in February, averaging 2.9 m/s (10 km/h), and lightest in October, at 1.4 m/s (5 km/h). The prevailing wind is from the SE.
What is the average temperature in Ko Samui year round?
The average temperature in Ko Samui over the whole year is 29°C. May is the hottest month, with highs of about 32°C; December is the coldest, with lows of about 26°C.