Koh Samui, Thailand
tropical climate · beach · medium crowds · mid prices
🏊 Swimmable sea this month (≥22°C)
Koh Samui sits in the tropics in Thailand, and the 2015–2024 weather record gives its sunshine a clear shape: the March peak reaches a 94/100 sun score, with daytime highs around 30°C — a solid base for a coastal escape.
The year runs from average lows of 25°C in December to highs of 31°C in May. The wet–dry contrast is pronounced: 86% rain-day odds in October against 35% in March. Beach-warm afternoons (24°C and up) hold through January–December.
Season by season (on the northern calendar), spring brings 31°C highs with 48% rain-day odds, summer 31°C at 55%, autumn 29°C at 79%, and winter 28°C at 53%. That makes spring the statistical sweet spot (season score 91), with summer a workable second; autumn is where the odds thin out. For warmth without the densest crowds, the shoulder play is January: still 28°C highs, with a sun score of 87.
Best months to visit Koh Samui
Our month-by-month scoring puts March first (94/100), with February (92) and April (90) close behind. Anything in January–December clears our 70-point reliability bar. The month to avoid on pure weather odds is November (73/100).
Put against its 126 tropical peers in March, it lands in the sunnier half of the group, ahead of 75% of them.
Month-by-month breakdown for Koh Samui → · More destinations for March →
Right now the 16-day outlook shows one mostly-clear day (under 40% cloud) and 16 with real rain risk, with temperatures between 23°C and 29°C — which is how Koh Samui earns its current 76/100 sun score.
Affiliate links — we may earn a commission, at no cost to you.
Flights from Europe
| From | Distance | Estimated non-stop time | |
|---|---|---|---|
| Brussels (BRU) | 9,582 km | ~12 h 30 | Find flights → |
| Amsterdam (AMS) | 9,515 km | ~12 h 30 | Find flights → |
| London (LON) | 9,872 km | ~12 h 45 | Find flights → |
| Paris (PAR) | 9,766 km | ~12 h 45 | Find flights → |
| Frankfurt (FRA) | 9,292 km | ~12 h | Find flights → |
Estimates from distance; actual schedules may require a connection.
Affiliate links — we may earn a commission, at no cost to you.
Next 16 days
Live forecast, refreshed twice daily. Forecasts updated 29 Oct, 06:36 CET.
| Date | High / low | Cloud | Rain odds |
|---|---|---|---|
| Thu 29 Oct | 27° / 24° | 96% | 89% |
| Fri 30 Oct | 29° / 25° | 88% | 78% |
| Sat 31 Oct | 28° / 24° | 82% | 72% |
| Sun 1 Nov | 29° / 25° | 58% | 53% |
| Mon 2 Nov | 28° / 25° | 39% | 43% |
| Tue 3 Nov | 28° / 25° | 57% | 56% |
| Wed 4 Nov | 29° / 25° | 56% | 70% |
| Thu 5 Nov | 28° / 25° | 90% | 64% |
| Fri 6 Nov | 29° / 24° | 79% | 68% |
| Sat 7 Nov | 28° / 24° | 77% | 80% |
| Sun 8 Nov | 28° / 24° | 96% | 89% |
| Mon 9 Nov | 27° / 24° | 92% | 85% |
| Tue 10 Nov | 27° / 23° | 76% | 76% |
| Wed 11 Nov | 28° / 24° | 83% | 75% |
| Thu 12 Nov | 28° / 24° | 96% | 80% |
| Fri 13 Nov | 28° / 26° | 98% | 77% |
Koh Samui climate, month by month
2015–2024 averages (March highlighted as the best month).
| Month | Day / night °C | Cloud | Rain-day odds | Sun score |
|---|---|---|---|---|
| January | 28° / 24.5° | 65% | 53.9% | 87 |
| February | 28.6° / 24.7° | 51.4% | 44.5% | 92 |
| March | 30° / 25.5° | 53.5% | 34.6% | 94 |
| April | 31° / 26.5° | 64.6% | 47.3% | 90 |
| May | 31.1° / 26.5° | 84% | 62.3% | 88 |
| June | 31.1° / 26.3° | 88.6% | 50.7% | 88 |
| July | 30.8° / 26° | 89.9% | 58.1% | 85 |
| August | 30.7° / 25.9° | 87.7% | 57.4% | 87 |
| September | 29.8° / 25.5° | 90.2% | 68.3% | 81 |
| October | 28.7° / 24.9° | 88.4% | 86.3% | 76 |
| November | 28.2° / 24.7° | 82.1% | 82.7% | 73 |
| December | 27.8° / 24.5° | 72.7% | 61.5% | 79 |
Similar sunny destinations
tropical escapes with a sun score within ±10 of Koh Samui right now.