Koh Samui weather live forecast

Today's maximum temperature in Koh Samui is expected to be 34°C. Select a day from the live weather forecast for Koh Samui, Thailand for more weather parameters.

Monday
25th May
34

28

9

UV11
Tuesday
26th May
33

28

8

UV11
Wednesday
27th May
33

28

8

UV10
Thursday
28th May
33

28

8

UV9
Friday
29th May
32

28

6

UV11

5-day weather forecast updated at 04:01 on Monday 25th May 2026 GMT

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The 5-day weather forecast for Thailand (Koh Samui) is provided by the Swiss meteorological agency, meteoblue. Find out more about our data sources.

Koh Samui weather forecast by day

Below are the detailed weather forecasts for Koh Samui for the next 5 days.

Koh Samui weather for Monday 25th May 2026

Expect isolated thunderstorms in Koh Samui, Thailand with a maximum temperature of 34°C, high levels of heat & humidity, maximum UV of 11+ (Extreme) and 9 hours of bright sunshine. There are 5-10 mm of rainfall expected with 77% chance of some rain and a gentle breeze of 19 kph from the west.

34
°C maximum temperature
28
°C minimum temperature
isolated thunderstorms
9
hours of sunshine
UV11
UV index (Extreme)
77
% chance of some rain
<10
mm of rainfall expected
H
high heat & humidity
19
kph wind from W

Koh Samui weather for Tuesday 26th May 2026

Expect isolated thunderstorms in Koh Samui, Thailand with a maximum temperature of 33°C, high levels of heat & humidity, maximum UV of 11 (Extreme) and 8 hours of bright sunshine. There are 5-10 mm of rainfall expected with 73% chance of some rain and a moderate breeze of 20 kph from the west.

33
°C maximum temperature
28
°C minimum temperature
isolated thunderstorms
8
hours of sunshine
UV11
UV index (Extreme)
73
% chance of some rain
<10
mm of rainfall expected
H
high heat & humidity
20
kph wind from W

Koh Samui weather for Wednesday 27th May 2026

Expect isolated thunderstorms in Koh Samui, Thailand with a maximum temperature of 33°C, high levels of heat & humidity, maximum UV of 10 (Very High) and 8 hours of bright sunshine. There are 5-10 mm of rainfall expected with 78% chance of some rain and a gentle breeze of 18 kph from the west.

33
°C maximum temperature
28
°C minimum temperature
isolated thunderstorms
8
hours of sunshine
UV10
UV index (Very High)
78
% chance of some rain
<10
mm of rainfall expected
H
high heat & humidity
18
kph wind from W

Koh Samui weather for Thursday 28th May 2026

Expect isolated thunderstorms in Koh Samui, Thailand with a maximum temperature of 33°C, high levels of heat & humidity, maximum UV of 9 (Very High) and 8 hours of bright sunshine. There are 5-10 mm of rainfall expected with 84% chance of some rain and a gentle breeze of 19 kph from the west.

33
°C maximum temperature
28
°C minimum temperature
isolated thunderstorms
8
hours of sunshine
UV9
UV index (Very High)
84
% chance of some rain
<10
mm of rainfall expected
H
high heat & humidity
19
kph wind from W

Koh Samui weather for Friday 29th May 2026

Expect isolated thunderstorms in Koh Samui, Thailand with a maximum temperature of 32°C, high levels of heat & humidity, maximum UV of 11 (Extreme) and 6 hours of bright sunshine. There are 10-20 mm of rainfall expected with 80% chance of some rain and a moderate breeze of 22 kph from the west.