TH Koh Samui · Spring

Visit Koh Samui
in May?

Good window in May — March is a notch above.

Open-Meteo · 10 years · 12 months compared · 9.51°N 100.06°E
88°FMax temperature
65%Rainy days
11.1hSunshine / day

Koh Samui weather in May

✅ Good
🌡️ Temperature min / max
79°F – 88°F
🌧 Rainy days
65% of days
☀️ Sunshine
11.1h per day on average
🌊 🌊 Season
Spring
⭐ ⭐ Weather score
7.2/10
📅 📅 Best month
March (7.9/10)

Should you visit Koh Samui in May?

✅ Good

✅ Yes if: you're willing to accept showers in exchange for lower prices and fewer tourists.

❌ No if: you're planning 100% outdoor activities — rain is frequent.

🌧 Rain : ██████░░░░ 65%
🌡 Temperature : ████████░░ 88°F
☀️ Sunshine : ████████░░ 11.1h/d

Our take: Koh Samui in May: 88°F and 11.1h of sunshine. Decent, but not the peak.

Koh Samui in May by trip type

What to expect in May

Spring marks the start of the good season in Koh Samui. Temperatures rise (31°F) and tourists have not yet arrived en masse. With 65% of rainy days, always have indoor alternatives planned. Not the best window, but acceptable if dates are constrained. March (7.9/10) is significantly better if possible.

All months for Koh Samui

Month-by-month comparison

MonthMin °FMax °FRain %Precip inSun h/dScore
🌤️ January75°F82°F57%0.2in10.9h7.6/10
🌤️ February77°F84°F48%0.1in11.0h7.8/10
🌤️ March79°F86°F35%0.1in11.0h7.9/10
🌤️ April79°F88°F49%0.1in11.2h7.4/10
⛅ May79°F88°F65%0.1in11.1h7.2/10
🌤️ June79°F88°F54%0.1in10.9h7.3/10
🌤️ July79°F88°F59%0.1in10.0h7.2/10
🌤️ August79°F88°F59%0.1in10.6h7.2/10
⛅ September79°F86°F67%0.2in10.0h7.1/10
🌧️ October77°F84°F88%0.3in9.9h7.0/10
⛅ November77°F82°F83%0.4in10.0h7.1/10
⛅ December75°F82°F63%0.3in10.5h7.4/10
Ideal Fair Challenging climate ◀ Current month · Source Open-Meteo · 10 years
📊 Data source Data based on 10 years of ERA5 records via Open-Meteo, with ECMWF seasonal adjustment. In May, Koh Samui averages 88°F, 65% rainy days and 11.1h of sunshine per day. Overall weather score: 7.2/10. See methodology →

May vs March (best month)

The best month is March (score 7.9/10). Difference:

FAQ — Koh Samui in May

Is May a good time to visit Koh Samui?
May is an acceptable time for Koh Samui (score 7.2/10). Conditions are decent but not optimal — consider March (7.9/10) if possible.
Does it rain a lot in Koh Samui in May?
Yes, 65% of days see rain in May. Plan some indoor activities as backup.

Find a place to stay in Koh Samui

Find places to stay in Koh Samui in May Search on Hotels.com

Activities and tours in Koh Samui

Guided tours, skip-the-line tickets and local experiences. Browse activities on GetYourGuide

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