The climate of Koh Tao is tropical, and the weather is hot and humid throughout the year. The temperature ranges between 28 degree Celsius to 32 degree Celsius. The peak tourist season is from November to April.
During these months, it is better to book in advance because of the high demand. Especially during the Christmas holiday season, hotels and resorts are often fully booked months ahead.
The best time to visit Koh Tao is in May and June when the weather is not too hot, and there are fewer tourists as well.