Destination
When should you visit Koh Samui?
Koh Samui, in the Gulf of Thailand, has palm-lined beaches, luxury resorts and the Ang Thong marine park on its doorstep. Its weather runs differently from Phuket and the rest of Thailand: Samui is fairly dry from January to September and gets its heavy rain from October to December. February to April is the best time to go. Here is how every month compares.
By Daan · Last reviewed October 2026
My recommendation
February & March
The driest, sunniest weeks with calm sea and great conditions for Ang Thong, before the April heat.
Best for Songkran
April
Thai New Year from April 13 to 15.
Best value
May–June
Hot and quieter, with lower prices.
Best in summer
July–August
Drier than Phuket in the same months.
Best for Christmas
December
Busy holidays, rain easing late in the month.
February scores
Plan around
What to know before you book
- Monsoon
- Heavy rain, rough sea. November is the wettest month.
- Ang Thong closure
- The marine park usually closes for part of the monsoon.
- High season
- Book holidays early.
October–December
Around November–December
December–February
Koh Samui travel tip
Pick your beach. Chaweng is the busiest with the most nightlife, Bophut's Fisherman's Village and Choeng Mon are calmer, and Lamai sits in between. Book a day trip to Ang Thong Marine Park in the dry months, and go early, before the wind picks up.
Month by month
All twelve months, at a glance
Tap any month for full scores, temperatures and planning notes.
- Temperature
- 24–29°C
- Warm, around 29°C, with some rain early.
- Crowds
- High
- Busy.
- Prices
- $$$$$
- High rates.
Ang Thong park trips run again by now.
- Beaches
- Snorkeling
- Temperature
- 25–29°C
- Warm, around 29°C, dry.
- Crowds
- High
- Busy.
- Prices
- $$$$$
- High rates.
Book Ang Thong boat tours early.
- Beaches
- Snorkeling
- Temperature
- 25–30°C
- Hot, around 30°C, mostly dry.
- Crowds
- Moderate-High
- Moderate.
- Prices
- $$$$
- Moderate rates.
Go to Ang Thong in the morning, before the wind picks up.
- Beaches
- Snorkeling
- Temperature
- 26–32°C
- Hot, around 32°C.
- Crowds
- Moderate-High
- Moderate, busy over Songkran.
- Prices
- $$$$
- Moderate rates.
Keep your phone in a waterproof pouch during Songkran.
- Beaches
- Songkran
- Temperature
- 26–33°C
- Hot, around 33°C, with showers.
- Crowds
- Moderate
- Quieter.
- Prices
- $$$
- Lower rates.
Book good hotels at shoulder prices.
- Beaches
- Spas
- Temperature
- 25–33°C
- Hot, around 33°C, with short showers.
- Crowds
- Moderate
- Quieter.
- Prices
- $$$
- Lower rates.
Samui is drier than Phuket in June.
- Beaches
- Spas
- Temperature
- 25–32°C
- Hot, around 32°C, with showers.
- Crowds
- Moderate-High
- Moderate to busy.
- Prices
- $$$$
- Moderate rates.
Check Full Moon Party dates on Koh Phangan.
- Beaches
- Families
- Temperature
- 25–32°C
- Hot, around 32°C, with showers.
- Crowds
- Moderate-High
- Busy.
- Prices
- $$$$
- Higher rates.
Chaweng is busiest. Stay in Bophut or Choeng Mon for calm.
- Beaches
- Families
- Temperature
- 25–32°C
- Hot, around 32°C, with showers.
- Crowds
- Moderate
- Quiet.
- Prices
- $$$
- Low rates.
Look for good hotel deals.
- Spas
- Quiet beaches
- Temperature
- 24–31°C
- Around 31°C, rain on 16 days.
- Crowds
- Low
- Quiet.
- Prices
- $$
- Low rates.
Have indoor plans for the heavy downpours.
- Spas
- Quiet stays
- Temperature
- 24–30°C
- Around 30°C, the wettest month.
- Crowds
- Low
- Very quiet.
- Prices
- $$
- Lowest rates.
Pick another month for a beach holiday.
- Spas
- Temperature
- 24–29°C
- Warm, around 29°C, with rain.
- Crowds
- Moderate-High
- Busy around the holidays.
- Prices
- $$$$
- Peak holiday rates.
Book Christmas and New Year early.
- Christmas
- Nightlife
Climate
Koh Samui weather by month
| Month | High | Low | Precipitation | Wet days |
|---|---|---|---|---|
| January | 29°C / 84°F | 24°C / 75°F | 127 mm | 9 |
| February | 29°C / 84°F | 25°C / 77°F | 64 mm | 4 |
| March | 30°C / 86°F | 25°C / 77°F | 116 mm | 5 |
| April | 32°C / 90°F | 26°C / 79°F | 83 mm | 6 |
| May | 33°C / 91°F | 26°C / 79°F | 132 mm | 11 |
| June | 33°C / 91°F | 25°C / 77°F | 134 mm | 10 |
| July | 32°C / 90°F | 25°C / 77°F | 117 mm | 11 |
| August | 32°C / 90°F | 25°C / 77°F | 102 mm | 11 |
| September | 32°C / 90°F | 25°C / 77°F | 118 mm | 11 |
| October | 31°C / 88°F | 24°C / 75°F | 295 mm | 16 |
| November | 30°C / 86°F | 24°C / 75°F | 445 mm | 17 |
| December | 29°C / 84°F | 24°C / 75°F | 263 mm | 12 |
Climate data: World Meteorological Organization (Ko Samui, 1991–2020). Temperatures are averages of daily highs and lows.
Ready to book February & March in Koh Samui?
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FAQ
Planning a trip to Koh Samui
What is the best month to visit Koh Samui?
February and March, with dry, sunny weather and calm sea.
When is the rainy season on Koh Samui?
Mostly October to December, later than in the rest of Thailand. November is the wettest month.