Koh Samui weather live forecast

Today's maximum temperature in Koh Samui is expected to be 90°F. Select a day from the live weather forecast for Koh Samui, Thailand for more weather parameters.

Monday
8th Dec
90

77

8

10
Tuesday
9th Dec
84

79

8

9
Wednesday
10th Dec
88

79

8

10
Thursday
11th Dec
86

79

5

3
Friday
12th Dec
84

77

3

8

5-day weather forecast updated at 04:02 on Monday 8th December 2025 GMT

More about Koh Samui

Koh Samui by month

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Recommended for Thailand

TUI: up to 7% off holidays booked online

Sale

Book online with TUI & save up to 7% on holidays
FREE child places available for select holidays
Pay £0 deposits with direct debit & spread the cost

Go to TUI deal >>

View all TUI offers

TUI deal finder

Destination

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 8th December 2025

Expect scattered clouds in Koh Samui, Thailand with a maximum temperature of 90°F, moderate levels of heat & humidity, maximum UV of 10 (Very High) and 8 hours of bright sunshine. There are 0 mm of rainfall expected and a gentle breeze of 9 mph from the north-east.

90
°F maximum temperature
77
°F minimum temperature
scattered clouds
8
hours of sunshine
10
UV index (Very High)
0
mm of rainfall expected
M
moderate heat & humidity
9
mph wind from NE

Koh Samui weather for Tuesday 9th December 2025

Expect scattered clouds in Koh Samui, Thailand with a maximum temperature of 84°F, moderate levels of heat & humidity, maximum UV of 9 (Very High) and 8 hours of bright sunshine. There are 0 mm of rainfall expected and a gentle breeze of 9 mph from the north-east.

84
°F maximum temperature
79
°F minimum temperature
scattered clouds
8
hours of sunshine
9
UV index (Very High)
0
mm of rainfall expected
M
moderate heat & humidity
9
mph wind from NE

Koh Samui weather for Wednesday 10th December 2025

Expect scattered clouds in Koh Samui, Thailand with a maximum temperature of 88°F, moderate levels of heat & humidity, maximum UV of 10 (Very High) and 8 hours of bright sunshine. There are 0 mm of rainfall expected and a gentle breeze of 9 mph from the north-east.

88
°F maximum temperature
79
°F minimum temperature
scattered clouds
8
hours of sunshine
10
UV index (Very High)
0
mm of rainfall expected
M
moderate heat & humidity
9
mph wind from NE

Koh Samui weather for Thursday 11th December 2025

Expect isolated thunderstorms in Koh Samui, Thailand with a maximum temperature of 86°F, moderate levels of heat & humidity, maximum UV of 3 (Moderate) and 5 hours of bright sunshine. There are 5-10 mm of rainfall expected with 73% chance of some rain and a gentle breeze of 9 mph from the north-east.

86
°F maximum temperature
79
°F minimum temperature
isolated thunderstorms
5
hours of sunshine
3
UV index (Moderate)
73
% chance of some rain
<10
mm of rainfall expected
M
moderate heat & humidity
9
mph wind from NE

Koh Samui weather for Friday 12th December 2025

Expect isolated thunderstorms in Koh Samui, Thailand with a maximum temperature of 84°F, moderate levels of heat & humidity, maximum UV of 8 (Very High) and 3 hours of bright sunshine. There are 30-40 mm of rainfall expected with 85% chance of some rain and a gentle breeze of 10 mph from the east.