Koh Samui, ThailandQuick decision
When to visit Koh Samui?
🌞 Best time overall
March
🌡️ Optimal temperature
79°F–86°F in March
🌧 Least rain
35% rainy days in March
🌧 Wettest month
October (88%)
📅 Best score
7.9/10
By trip type
Best time by type of trip
BeachesDecember–April — Chaweng, Lamai and south coast beaches.
Big Buddha & TemplesYear-round — Wat Phra Yai, Wat Plai Laem and Secret Buddha Garden.
Spa & WellnessYear-round — spa resorts, detox and yoga retreats.
Full Moon PartyYear-round — neighbouring Koh Phangan, monthly party (30 min ferry).
FamilyJanuary–March — calm beaches, Aquapark and Ang Thong excursions.
Monthly climate data
Koh Samui weather month by month
| Month | Min °F | Max °F | Rainy days (%) | Precip. in/d | Sun h/d | Score |
|---|---|---|---|---|---|---|
| 🌤️ January | 75°F | 82°F | 57% | 0.2in | 10.9h | 7.6/10 |
| 🌤️ February | 77°F | 84°F | 48% | 0.1in | 11.0h | 7.8/10 |
| 🌤️ March | 79°F | 86°F | 35% | 0.1in | 11.0h | 7.9/10 |
| 🌤️ April | 79°F | 88°F | 49% | 0.1in | 11.2h | 7.4/10 |
| ⛅ May | 79°F | 88°F | 65% | 0.1in | 11.1h | 7.2/10 |
| 🌤️ June | 79°F | 88°F | 54% | 0.1in | 10.9h | 7.3/10 |
| 🌤️ July | 79°F | 88°F | 59% | 0.1in | 10.0h | 7.2/10 |
| 🌤️ August | 79°F | 88°F | 59% | 0.1in | 10.6h | 7.2/10 |
| ⛅ September | 79°F | 86°F | 67% | 0.2in | 10.0h | 7.1/10 |
| 🌦️ October | 77°F | 84°F | 88% | 0.3in | 9.9h | 7.0/10 |
| ⛅ November | 77°F | 82°F | 83% | 0.4in | 10.0h | 7.1/10 |
| ⛅ December | 75°F | 82°F | 63% | 0.3in | 10.5h | 7.4/10 |
Ideal
Fair
Challenging climate
Source: Open-Meteo · 10 years
🌴 Tropical destination — heavy rain months benefit from an algorithmic adjustment: tropical showers are intense but brief and usually don't ruin a trip.
Seasonal breakdown
What to expect each season
🌸 Spring (Mar–May) — Good time
Average 31°F, 50% rainy days, 11.1h sunshine/day. Score: 7.5/10.
☀️ Summer (Jun–Aug) — Good time
Average 31°F, 57% rainy days, 10.5h sunshine/day. Score: 7.2/10.
🍂 Autumn (Sep–Nov) — Good time
Average 29°F, 79% rainy days, 10.0h sunshine/day. Score: 7.1/10.
❄️ Winter (Dec–Feb) — Good time
Average 28°F, 56% rainy days, 10.8h sunshine/day. Score: 7.6/10.
Accommodation
Find a place to stay in Koh Samui
Check availability during the recommended period
Tip : off-peak months (October, November) are cheapest but weather is significantly worse.
Search on Hotels.comActivities & tours
Activities and tours in Koh Samui
Guided tours, skip-the-line tickets and local experiences.
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Flights
Find a flight to Koh Samui
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Monthly weather
Detailed weather by month
FAQ
Frequently asked questions
March is ideal with 35% rainy days and 30°F.
October is the wettest month with 88% rainy days.
Yes, March is the best month with an average of 30°F.
In winter, the average score is 7.6/10. Acceptable conditions for cultural visits.
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