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Ko Samui Weather

Ko Samui weather today, the 14-day forecast, and average temperature, rain and what to wear for every month — compared against Hong Kong. Best months to visit: Jan, Feb, Mar, Apr, Jul and Aug.

Ko Samui current weather

Ko Samui now (local time 11:30)

29°C

Overcast

Feels like
35°
Humidity
74%
Wind
10 km/h

Next 7 days · what to wear

25° – 30°C

Rain likely on 7 of 7 days

👕 Short sleeves, plus a light layer for air-conditioned interiors; it's wet, so pack a compact umbrella.

Ko Samui 14-day forecast

  1. Today

    10/4

    🌦️

    30°

    26°

    💧59%

  2. Mon

    10/5

    🌦️

    29°

    25°

    💧73%

  3. Tue

    10/6

    ⛈️

    29°

    25°

    💧96%

  4. Wed

    10/7

    ⛈️

    29°

    25°

    💧96%

  5. Thu

    10/8

    ⛈️

    28°

    25°

    💧93%

  6. Fri

    10/9

    🌦️

    28°

    25°

    💧88%

  7. Sat

    10/10

    🌦️

    27°

    25°

    💧98%

  8. Sun

    10/11

    ⛈️

    28°

    24°

    💧94%

  9. Mon

    10/12

    🌦️

    27°

    25°

    💧92%

  10. Tue

    10/13

    🌦️

    28°

    26°

    💧88%

  11. Wed

    10/14

    🌦️

    29°

    26°

    💧92%

  12. Thu

    10/15

    ⛈️

    29°

    25°

    💧87%

  13. Fri

    10/16

    🌦️

    29°

    25°

    💧89%

  14. Sat

    10/17

    🌦️

    29°

    25°

    💧84%

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Best time to visit Ko Samui

On temperature and rainfall, the most comfortable months in Ko Samui are Jan, Feb, Mar, Apr, Jul and Aug. The hottest month is May (average high 30°C) and the coldest is January (average low 26°C).

Jan28°26°Feb28°26°Mar29°27°Apr30°28°May30°29°Jun30°28°Jul29°28°Aug29°27°Sep29°27°Oct28°27°Nov28°27°Dec28°27°

Ko Samui climate by month

MonthAvg highAvg lowRainHumidityvs Hong Kong
JanBest28°C26°C135 mm80%+10°C
FebBest28°C26°C38 mm79%+10°C
MarBest29°C27°C114 mm78%+8°C
AprBest30°C28°C90 mm77%+6°C
May30°C29°C170 mm78%+3°C
Jun30°C28°C167 mm80%0°C
JulBest29°C28°C166 mm80%-1°C
AugBest29°C27°C144 mm81%-1°C
Sep29°C27°C181 mm81%0°C
Oct28°C27°C246 mm81%+2°C
Nov28°C27°C375 mm81%+5°C
Dec28°C27°C262 mm80%+9°C

Data: NASA POWER 2001–2020 climatology (MERRA-2, elevation-corrected); Hong Kong comparison uses HKO 1991–2020 normals.

Ko Samui weather month by month: what to wear

Ko Samui in OctoberThis month

October in Ko Samui is warm to hot: average highs of 28°C and lows of 27°C, around 246 mm of rain (wet) and 81% humidity — about 2°C warmer than Hong Kong.

👕 Short sleeves, plus a light layer for air-conditioned interiors; it's wet, so pack a compact umbrella; humid, so quick-dry fabrics help.

Ko Samui in November

November in Ko Samui is warm to hot: average highs of 28°C and lows of 27°C, around 375 mm of rain (very wet) and 81% humidity — about 5°C warmer than Hong Kong.

👕 Short sleeves, plus a light layer for air-conditioned interiors; it's wet, so pack a compact umbrella; humid, so quick-dry fabrics help.

Ko Samui in December

December in Ko Samui is warm to hot: average highs of 28°C and lows of 27°C, around 262 mm of rain (very wet) and 80% humidity — about 9°C warmer than Hong Kong.

👕 Short sleeves, plus a light layer for air-conditioned interiors; it's wet, so pack a compact umbrella; humid, so quick-dry fabrics help.

Ko Samui in JanuaryBest month

January in Ko Samui is warm to hot: average highs of 28°C and lows of 26°C, around 135 mm of rain (some rain) and 80% humidity — about 10°C warmer than Hong Kong. It's one of the most comfortable months of the year to visit.

👕 Short sleeves, plus a light layer for air-conditioned interiors; humid, so quick-dry fabrics help.

Ko Samui in FebruaryBest month

February in Ko Samui is warm to hot: average highs of 28°C and lows of 26°C, around 38 mm of rain (mostly dry) and 79% humidity — about 10°C warmer than Hong Kong. It's one of the most comfortable months of the year to visit.

👕 Short sleeves, plus a light layer for air-conditioned interiors.

Ko Samui in MarchBest month

March in Ko Samui is warm to hot: average highs of 29°C and lows of 27°C, around 114 mm of rain (some rain) and 78% humidity — about 8°C warmer than Hong Kong. It's one of the most comfortable months of the year to visit.

👕 Short sleeves, plus a light layer for air-conditioned interiors.

Ko Samui in AprilBest month

April in Ko Samui is warm to hot: average highs of 30°C and lows of 28°C, around 90 mm of rain (some rain) and 77% humidity — about 6°C warmer than Hong Kong. It's one of the most comfortable months of the year to visit.

👕 Short sleeves, plus a light layer for air-conditioned interiors.

Ko Samui in May

May in Ko Samui is warm to hot: average highs of 30°C and lows of 29°C, around 170 mm of rain (wet) and 78% humidity — about 3°C warmer than Hong Kong.

👕 T-shirts, shorts and breathable fabrics; sunscreen and water; it's wet, so pack a compact umbrella.

Ko Samui in June

June in Ko Samui is warm to hot: average highs of 30°C and lows of 28°C, around 167 mm of rain (wet) and 80% humidity — about the same as Hong Kong.

👕 Short sleeves, plus a light layer for air-conditioned interiors; it's wet, so pack a compact umbrella; humid, so quick-dry fabrics help.

Ko Samui in JulyBest month

July in Ko Samui is warm to hot: average highs of 29°C and lows of 28°C, around 166 mm of rain (wet) and 80% humidity — about the same as Hong Kong. It's one of the most comfortable months of the year to visit.

👕 Short sleeves, plus a light layer for air-conditioned interiors; it's wet, so pack a compact umbrella; humid, so quick-dry fabrics help.

Ko Samui in AugustBest month

August in Ko Samui is warm to hot: average highs of 29°C and lows of 27°C, around 144 mm of rain (some rain) and 81% humidity — about the same as Hong Kong. It's one of the most comfortable months of the year to visit.

👕 Short sleeves, plus a light layer for air-conditioned interiors; humid, so quick-dry fabrics help.

Ko Samui in September

September in Ko Samui is warm to hot: average highs of 29°C and lows of 27°C, around 181 mm of rain (wet) and 81% humidity — about the same as Hong Kong.

👕 Short sleeves, plus a light layer for air-conditioned interiors; it's wet, so pack a compact umbrella; humid, so quick-dry fabrics help.

FAQ

›What is the best time to visit Ko Samui?

On temperature and rainfall, the most comfortable months in Ko Samui are Jan, Feb, Mar, Apr, Jul and Aug. The hottest month is May (average high 30°C) and the coldest is January (average low 26°C).

›What's the weather like in Ko Samui in October, and what should I wear?

October in Ko Samui is warm to hot: average highs of 28°C and lows of 27°C, around 246 mm of rain (wet) and 81% humidity — about 2°C warmer than Hong Kong. What to wear: Short sleeves, plus a light layer for air-conditioned interiors; it's wet, so pack a compact umbrella; humid, so quick-dry fabrics help.

›What's the weather like in Ko Samui in November, and what should I wear?

November in Ko Samui is warm to hot: average highs of 28°C and lows of 27°C, around 375 mm of rain (very wet) and 81% humidity — about 5°C warmer than Hong Kong. What to wear: Short sleeves, plus a light layer for air-conditioned interiors; it's wet, so pack a compact umbrella; humid, so quick-dry fabrics help.

›When is the rainy season in Ko Samui?

Ko Samui is wettest in November, with about 375 mm on average, and driest in February, with about 38 mm.

›How cold does Ko Samui get? Does it snow?

The coldest month is January, averaging 28°C by day and 26°C at night. Snow is very unlikely.

Planning a trip to Ko Samui?

More Thailand weather

Bangkok24–31°Chiang Mai22–29°Phuket24–29°Krabi26–28°Ayutthaya23–31°Pattaya27–29°Chiang Rai●21–30°

Popular destinations in October

Tokyo●14–22°Osaka●14–23°Fukuoka●16–23°Sapporo●7–16°Okinawa (Naha)●24–28°Kyoto●13–22°Nagoya●14–23°Seoul●9–19°Busan●13–21°Jeju Island●16–21°Taipei22–27°Taichung●22–30°

Forecast data: Open-Meteo.com (CC BY 4.0), refreshed every 3 hours. Hottest month: May; coldest: January.