Beach Weather
Comprehensive weather and environmental data for Koh Samui
22°-33°CAnnual Temperature
1950mmAnnual Rainfall
27°-30°CSea Temperature
52kmCoastline
MayNow
May Weather
Monsoon SeasonGood Weather
Temperature25° - 32°CFeels like 33° - 35°C
Humidity82%very high
Rainfall130mm11 rainy days
Sunshine6 hrs/dayCloudy mornings; afternoon rain
Wind19-28 km/hSouthwest monsoon
Waves1-1.5mGentle-Moderate
Sea Temperature30°CExcellent
Water Visibility20-30mexcellent
Best For This Month
Rainfall Pattern:Monsoon begins; frequent showers
UV Index
11Extreme
Peak Hours: 9 AM - 3 PM
Burn Time: 12-15 minutes
SPF 50+ sunscreen mandatory. Reapply every 2 hours.
Air Quality
72Moderate
PM2.5: 24-28 µg/m³
PM10: 35-42 µg/m³
Acceptable for most
Data based on 3-year averages (2023-2026). Actual conditions may vary. Always observe local flag warnings on the beach.