From January to March you can expect good weather in Koh Samui, with little if any rain, and refreshing winds helping to keep temperatures more moderate. From March, temperature starts to rise, usually reaching peak levels in April and May.
In May and June a little rain is expected in Koh Samui, usually in the form of an hour-long afternoon shower, clearing the way for more blue skies and bright sunshine. In September the monsoon is expected, bringing plenty of rainfall and a rise in humidity. Rainfall usually peaks between October and November.
Overall weather conditions in Koh Samui
✦-perfect ✦-very good ✦-good ✦-uncomfy ✦-better stay home!
The best time to avoid rain in Koh Samui
✦ - chance of getting wet is close to minimum
✦ - a bit of rain every few days might be expected
✦ - the rain isn't constant and long lasting, if any
✦ - chances of rainy day are higher than 50/50
✦ - not only umbrella can be handy, boat too!
Weather of Thailand regions
Thailand is big and at the same time the weather may vary a lot in different regions of the country. If you are planning to visit other parts of the country too, check what is the weather in all Thailand regions.
Thailand weather by month
Thailand weather changes significantly throughout the year. Check Thailand weather by month and get an idea what weather should be expected at the time of your visit.
The best time to visit Thailand
The peak tourism season of Thailand is the cool season lasting from November to February when the weather is coolest and driest but the country can be visited outside the peak tourism season - just choose the best time for your Thailand trip plan!