Koh Samui Weather and Climate: A Comprehensive Guide
The weather in Koh Samui is characterized by a steady average temperature throughout the year.
It also experiences much rainfall throughout the year.
Let's now guide you through the climate details for a complete overview.
Average maximum day and minimum night temperature
The climate in Koh Samui remains fairly constant, offering comfortable temperatures throughout the year. Average daytime temperatures reach a very warm 31°C in May. In January, the coolest month of the year, temperatures drop to a comfortable 29°C.
At night, you can expect cooler temperatures, with averages dropping to around 26°C during this month. Check out our detailed temperature page for more information.Temperature ranges by month
Precipitation and rainy days
Koh Samui is known for its substantial rainfall, with annual precipitation reaching 1645 mm. Koh Samui can be quite wet during October, receiving approximately 296 mm of precipitation over 20 rainy days. In contrast February, experiences much drier conditions, with 44 mm of rainfall, spread across 5 rainy days. For more details, please visit our Koh Samui Precipitation page.The mean monthly precipitation over the year, including rain, hail and snow
The average number of days each month with precipitation
Sunshine over the year
Koh Samui can be enjoyed more throughout the sunniest month of March under a blue sky, with approximately 8.0 hours of sunshine daily. In contrast, the city experiences much darker days in September, with only 4.8 hours of sunlight per day. Visit our detailed sunshine hours page for more information.Monthly hours of sunshine
Daily hours of sunshine
Average water temperature
The mean water temperature over the year ranges from 27°C in January to 30°C in April.
Water temperature over the year
Average humidity
The city experiences its highest humidity in October, reaching 85%. In June, the humidity drops to its lowest level at 78%. What does this mean? Read our detailed page on humidity levels for further details.
Relative humidity over the year
partly cloudy and small chance of slight rain broken clouds and no rain partly cloudy and chance of slight rainForecast for Koh Samui
7 m/s
5 m/s
6 m/s
Select a Month of Interest
Check the conditions for any month of the year.
The best time of year to visit Koh Samui in Thailand
Other facts from our historical weather data:Most rainfall (rainy season) is seen in September, October, November and December.
May has an average maximum temperature of 31°C and is the hottest month of the year.
The coolest month is January with an average maximum temperature of 29°C.
October tops the wettest month list with 296 mm of rainfall.
February is the driest month with 44 mm of precipitation.
March is the sunniest month with an average of 240 hours of sunshine.
No idea where to travel to this year? We have a tool that recommends destinations based on your ideal conditions. Find out where to go with our weather planner.
