Koh Samui weather live forecast

Today's maximum temperature in Koh Samui is expected to be 32°C. Select a day from the live weather forecast for Koh Samui, Thailand for more weather parameters.

5-day weather forecast updated at 04:02 on Friday 5th September 2025 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 Friday 5th September 2025

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 8 hours of bright sunshine. There are 0-2 mm of rainfall expected with 51% chance of some rain and a gentle breeze of 14 kph from the west.

  • 32°C maximum temperature32
    °C maximum temperature
  • 27°C minimum temperature27
    °C minimum temperature
  • Isolated thunderstorms
    isolated thunderstorms
  • 8 hours of bright sunshine8
    hours of sunshine
  • UV (maximum) index 11+ (Extreme)11
    UV index (Extreme)
  • 51% chance of some rain51
    % chance of some rain
  • 0-2 mm of rainfall expected<2
    mm of rainfall expected
  • High heat & humidityH
    high heat & humidity
  • Gentle breeze of 14 kph from the West14
    kph wind from W

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Koh Samui weather for Saturday 6th September 2025

Expect isolated thunderstorms in Koh Samui, Thailand with a maximum temperature of 30°C, moderate levels of heat & humidity, maximum UV of 11 (Extreme) and 9 hours of bright sunshine. There are 50 mm or more of rainfall expected with 68% chance of some rain and a gentle breeze of 14 kph from the west.

  • 30°C maximum temperature30
    °C maximum temperature
  • 27°C minimum temperature27
    °C minimum temperature
  • Isolated thunderstorms
    isolated thunderstorms
  • 9 hours of bright sunshine9
    hours of sunshine
  • UV (maximum) index 11 (Extreme)11
    UV index (Extreme)
  • 68% chance of some rain68
    % chance of some rain
  • 50 mm or more of rainfall expected>50
    mm or more of rainfall expected
  • Moderate heat & humidityM
    moderate heat & humidity
  • Gentle breeze of 14 kph from the West14
    kph wind from W

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Koh Samui weather for Sunday 7th September 2025

Expect isolated thunderstorms in Koh Samui, Thailand with a maximum temperature of 31°C, moderate levels of heat & humidity, maximum UV of 9 (Very High) and 8 hours of bright sunshine. There are 20-30 mm of rainfall expected with 77% chance of some rain and a light breeze of 12 kph from the west.

  • 31°C maximum temperature31
    °C maximum temperature
  • 27°C minimum temperature27
    °C minimum temperature
  • Isolated thunderstorms
    isolated thunderstorms
  • 8 hours of bright sunshine8
    hours of sunshine
  • UV (maximum) index 9 (Very High)9
    UV index (Very High)
  • 77% chance of some rain77
    % chance of some rain
  • 20-30 mm of rainfall expected<30
    mm of rainfall expected
  • Moderate heat & humidityM
    moderate heat & humidity
  • Light breeze of 12 kph from the West12
    kph wind from W

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Koh Samui weather for Monday 8th September 2025

Expect isolated thunderstorms in Koh Samui, Thailand with a maximum temperature of 31°C, moderate levels of heat & humidity, maximum UV of 10 (Very High) and 8 hours of bright sunshine. There are 10-20 mm of rainfall expected with 68% chance of some rain and a light breeze of 11 kph from the west.

  • 31°C maximum temperature31
    °C maximum temperature
  • 27°C minimum temperature27
    °C minimum temperature
  • Isolated thunderstorms
    isolated thunderstorms
  • 8 hours of bright sunshine8
    hours of sunshine
  • UV (maximum) index 10 (Very High)10
    UV index (Very High)
  • 68% chance of some rain68
    % chance of some rain
  • 10-20 mm of rainfall expected<20
    mm of rainfall expected
  • Moderate heat & humidityM
    moderate heat & humidity
  • Light breeze of 11 kph from the West11
    kph wind from W

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Koh Samui weather for Tuesday 9th September 2025

Expect isolated thunderstorms in Koh Samui, Thailand with a maximum temperature of 31°C, moderate 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 81% chance of some rain and a light breeze of 8 kph from the west.

  • 31°C maximum temperature31
    °C maximum temperature
  • 27°C minimum temperature27
    °C minimum temperature
  • Isolated thunderstorms
    isolated thunderstorms
  • 8 hours of bright sunshine8
    hours of sunshine
  • UV (maximum) index 10 (Very High)10
    UV index (Very High)
  • 81% chance of some rain81
    % chance of some rain
  • 5-10 mm of rainfall expected<10
    mm of rainfall expected
  • Moderate heat & humidityM
    moderate heat & humidity
  • Light breeze of 8 kph from the West8
    kph wind from W

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Metric (°C / mm)  |  Imperial (°F / inches)

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