Koh Samui, ThailandQuick decision
When to visit Koh Samui?
🌞 Best time overall
March
🌡️ Optimal temperature
26°C–30°C 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 °C | Max °C | Rainy days (%) | Precip. mm/d | Sun h/d | Score |
|---|---|---|---|---|---|---|
| 🌤️ January | 24°C | 28°C | 57% | 4.3 | 10.9h | 7.6/10 |
| 🌤️ February | 25°C | 29°C | 48% | 2.1 | 11.0h | 7.8/10 |
| 🌤️ March | 26°C | 30°C | 35% | 1.4 | 11.0h | 7.9/10 |
| 🌤️ April | 26°C | 31°C | 49% | 3.6 | 11.2h | 7.4/10 |
| ⛅ May | 26°C | 31°C | 65% | 3.8 | 11.1h | 7.2/10 |
| 🌤️ June | 26°C | 31°C | 54% | 2.5 | 10.9h | 7.3/10 |
| 🌤️ July | 26°C | 31°C | 59% | 3.2 | 10.0h | 7.2/10 |
| 🌤️ August | 26°C | 31°C | 59% | 2.7 | 10.6h | 7.2/10 |
| ⛅ September | 26°C | 30°C | 67% | 4.4 | 10.0h | 7.1/10 |
| 🌦️ October | 25°C | 29°C | 88% | 7.3 | 9.9h | 7.0/10 |
| ⛅ November | 25°C | 28°C | 83% | 9.5 | 10.0h | 7.1/10 |
| ⛅ December | 24°C | 28°C | 63% | 7.2 | 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°C, 50% rainy days, 11.1h sunshine/day. Score: 7.5/10.
☀️ Summer (Jun–Aug) — Good time
Average 31°C, 57% rainy days, 10.5h sunshine/day. Score: 7.2/10.
🍂 Autumn (Sep–Nov) — Good time
Average 29°C, 79% rainy days, 10.0h sunshine/day. Score: 7.1/10.
❄️ Winter (Dec–Feb) — Good time
Average 28°C, 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.
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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°C.
October is the wettest month with 88% rainy days.
Yes, March is the best month with an average of 30°C.
In winter, the average score is 7.6/10. Acceptable conditions for cultural visits.
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