Ko Samui weather
At 1:30 AM local time it was drizzle and 25°C (77°F). Mostly light, on-and-off rain; heavier around 1 AM (3.6 mm total). Best months for weather: Feb–Apr. Below: today's sky, the hour-by-hour rain chance and the 16-day forecast for Ko Samui, Surat Thani, Thailand.
Current conditions
- Clouds
- 65%
- Chance of rain
- 67%
- Rain
- 1.2 mm/h
Hourly Forecast
Mostly light, on-and-off rain; heavier around 1 AM (3.6 mm total)
Daily Forecast
Best Time to Visit
Peak season Feb–AprOff season Oct–Dec
About Ko Samui weather
Is it raining in Ko Samui right now?
Yes. It’s drizzle and 25° right now. Mostly light, on-and-off rain; heavier around 1 AM (3.6 mm total).
What’s the weather like in Ko Samui this week?
Over the next 7 days, expect highs of 28–30° and lows of 24–26°. Rain is likely on 7 of 7 days (Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday). The driest day looks like Monday.
Has it been raining in Ko Samui lately?
In the past 7 days, Ko Samui had 6 rainy days and 114.2 mm of rain in total.
What should I pack for Ko Samui?
For the coming week, bring an umbrella or rain jacket, light, breathable clothes and sunscreen.
Ko Samui weather by month
When is the best time to visit Ko Samui?
Based on weather alone, the best time to visit Ko Samui is Feb–Apr, according to NASA's 2001–2025 climate averages. Oct–Dec tends to be the least pleasant. Average highs run from 27°C (81°F) in January to 30°C (86°F) in May.
What is the rainiest month in Ko Samui?
November is the wettest month, with about 375 mm (14.8 in) of rain on average. February is the driest, with about 38 mm (1.5 in).
What is the hottest month in Ko Samui?
May is the warmest, with average highs of 30°C (86°F) and lows of 28°C (83°F). January is the coolest, with highs of 27°C (81°F) and lows of 26°C (79°F).
Does Ko Samui have a rainy season?
Yes. May–Jul, Sep–Dec is the rainy season (150 mm or more a month), while Feb is usually dry (under 60 mm).
How warm is the sea in Ko Samui?
The sea is warmest in May at about 32°C (90°F) and coolest in December at about 29°C (83°F). It is warm enough for swimming all year.
Ko Samui weather month by month
Sources: 2001–2025 monthly averages from NASA POWER (MERRA-2 reanalysis), sea temperature from Open-Meteo Marine, forecast and current conditions from Open-Meteo. Page updated . How we rate months