Warm
Average highs sit around 29°C, giving warm days by monthly-average standards.
January verdict
Koh Samui, Thailand in January
Weather score73Very good
Very good for holiday weather
Average highs sit around 29°C, giving warm days by monthly-average standards. Sunshine averages 7.1h per day, enough for a balanced month. Rainfall averages 123mm, so some wet days are possible.
January weather
Monthly averages
Temp
29°C
Rain
123mm
Sun
7.1h
Sea
28°C
Weather score
73
Very good
Seasonal climate calendar
TemperatureTemp
RainRain
SunSun
SwimSwim
Weather scoreWeather score
Trip feel
Showers
Rainfall averages 123mm, so some wet days are possible.
Some sun
Sunshine averages 7.1h per day, enough for a balanced month.
Warm sea
Sea temperatures average 28°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
January29°C average high
January is cooler than the yearly average, which can make sightseeing feel gentler than in hotter months.
Warmest monthsApril to September
This stretch sets the upper range for average daytime heat.
Rain
January123mm average rain
January 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
January7.1 hours average sun
January sits close to Koh Samui's yearly sunshine average, so it is a middle-of-the-pack month for bright days.
Brightest monthsFebruary to April
This stretch has the strongest sunshine in the monthly averages.
Sea temperature
January28°C average sea
January is one of the cooler sea months locally, though the water still averages warm enough for most swimmers.
Warmest seaApril to September
Sea temperatures are usually near 30°C in this stretch, so swimming comfort is at its strongest.
Weather score
January73 weather score
January scores above Koh Samui's yearly average, so the overall weather mix is stronger than most months.
Best weather monthsFebruary to March
These months have the strongest weather score in the monthly averages.
