Thailand
Koh Samui Weather & Climate
Coconut palms, full moon parties and the Gulf of Thailand's most developed island
29°C
Max sea
30°C
Max air
February
Best month
55mm
Driest month
Coconut palms, full moon parties and the Gulf of Thailand's most developed island
Koh Samui is the Gulf of Thailand's largest island and its most developed, yet it has managed to retain pockets of genuine tropical paradise amid the resort sprawl. The beaches vary enormously: Chaweng on the east coast is long, lively and lined with beach bars; Bophut in the north is quieter and more characterful, with a charming Fisherman's Village; Lamai has a good balance of activity and relaxation. The island's interior is covered in coconut palms — Samui was historically one of Thailand's great coconut exporters — and the mountain spine offers waterfalls, temples and excellent views.
When to go: December to April is dry season. The opposite side of the Gulf from Phuket — when one is wet the other is dry.
The best months to visit Koh Samui are February, March, April. Peak season is March with the best combination of warm temperatures and low rainfall.
| Month | Air | Sea | Rain | UV | Wind |
|---|---|---|---|---|---|
| Jan | 26°C | 27°C | 134mm | 8 | 18 |
| Feb | 28°C | 27°C | 57mm | 9 | 18 |
| Mar | 29°C | 28°C | 55mm | 10 | 18 |
| Apr | 30°C | 29°C | 86mm | 11 | 17 |
| May | 30°C | 29°C | 165mm | 10 | 17 |
| Jun | 29°C | 29°C | 131mm | 9 | 18 |
| Jul | 28°C | 28°C | 132mm | 9 | 18 |
| Aug | 28°C | 28°C | 170mm | 9 | 18 |
| Sep | 28°C | 28°C | 281mm | 9 | 18 |
| Oct | 27°C | 27°C | 400mm | 10 | 17 |
| Nov | 25°C | 26°C | 551mm | 9 | 17 |
| Dec | 25°C | 26°C | 216mm | 8 | 17 |
The best time to visit Koh Samui is February, March, April. Peak season is March when temperatures reach 29°C with very little rain. December to April is dry season. The opposite side of the Gulf from Phuket — when one is wet the other is dry.
Sea temperatures in Koh Samui range from 26°C in November to 29°C in April. The sea is bath-warm at its warmest.
Winter temperatures in Koh Samui average 26°C with sea temperatures of 26°C. This makes it a great winter sun destination.
The driest month is March with 55mm. The wettest month sees 551mm. Koh Samui receives 2378mm annually.
Warm and very warm seas. Moderate rainfall (134mm). UV 8. Sun protection essential.
Hot and very warm seas. Very little rain (57mm). UV 9. Sun protection essential.
Hot and bath-warm seas. Very little rain (55mm). UV 10. Sun protection essential.
Hot and bath-warm seas. Some rain (86mm). UV 11. Sun protection essential.
Hot and bath-warm seas. Moderate rainfall (165mm). UV 10. Sun protection essential.
Hot and bath-warm seas. Moderate rainfall (131mm). UV 9. Sun protection essential.
Hot and bath-warm seas. Moderate rainfall (132mm). UV 9. Sun protection essential.
Hot and bath-warm seas. Moderate rainfall (170mm). UV 9. Sun protection essential.
Hot and bath-warm seas. Heavy rainfall (281mm). UV 9. Sun protection essential.
Warm and very warm seas. Heavy rainfall (400mm). UV 10. Sun protection essential.
Warm and very warm seas. Heavy rainfall (551mm). UV 9. Sun protection essential.
Warm and very warm seas. Heavy rainfall (216mm). UV 8. Sun protection essential.
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