Due to its proximity to equator, ko pha Ngan’s climate remains tropical with an average temperature of 25 degree C – 34 degree C, with lots of sunshine, high humidity and occasional showers.There are two seasons in Southern Thailand: wet and dry. Although the temperature in ko pha Ngan tends to remain fairly constant year round, it would be better to avoid the months of September and November as they can be quite wet. The dry season tends to be from February to April. The best time to visit ko pha Ngan is between December-March when the water is high, clean, and good for swimming. Even July/August can be good months to go since the water rises during this period after the dry season.
Dry season (Mid December– April): The climate remains mostly dry and relatively cool.
Hot season (May– September): It can be very hot with occasional storms.
Wet season (October– Mid December): There can be a strong and windy monsoon with lots of rain.