Hot
Average highs reach 32°C, so days can feel very hot.
May verdict
Koh Samui, Thailand in May
Weather score58Good
Good for holiday weather
Average highs reach 32°C, so days can feel very hot. Sunshine averages 6.3h per day, enough for a balanced month. Rainfall averages 172mm, so some wet days are possible.
May weather
Monthly averages
Temp
32°C
Rain
172mm
Sun
6.3h
Sea
30°C
Weather score
58
Good
Seasonal climate calendar
TemperatureTemp
RainRain
SunSun
SwimSwim
Weather scoreWeather score
Trip feel
Showers
Rainfall averages 172mm, so some wet days are possible.
Some sun
Sunshine averages 6.3h per day, enough for a balanced month.
Warm sea
Sea temperatures average 30°C, so swimming is usually comfortable by monthly-average standards.
Map
Weather map
Compare Koh Samui, Thailand with nearby places by weather score, rain, sun, temperature, and swim conditions.
Temperature
May32°C average high
May is one of Koh Samui's warmest months, with daytime heat above the yearly average.
Warmest monthsApril to September
This stretch sets the upper range for average daytime heat.
Rain
May172mm average rain
May sits on the drier side of Koh Samui's year, which helps with sightseeing and transfers.
Driest monthsJanuary to September
This is the drier part of the year, when outdoor plans usually need less weather flexibility.
Sun
May6.3 hours average sun
May is below Koh Samui's yearly sunshine average, so bright-day planning is less reliable than in peak months.
Brightest monthsFebruary to April
This stretch has the strongest sunshine in the monthly averages.
Sea temperature
May30°C average sea
May is one of Koh Samui's warmest sea months, when swimming comfort is usually strongest.
Warmest seaApril to September
Sea temperatures are usually near 30°C in this stretch, so swimming comfort is at its strongest.
Weather score
May58 weather score
May scores below Koh Samui's yearly average, so the weather trade-offs are more noticeable.
Best weather monthsFebruary to March
These months have the strongest weather score in the monthly averages.
