High Season: January • February
No matter where you are in Thailand, January and February are fantastic. The north is cool in the mountains, the south has little chance of rainfall, and golden sunlight bathes the majority of the gulf, with the exception of Koh Samui, which still sees intermittent showers.
Shoulder Season: March • April • October • November
March and April, as well as October and November, bookend the dry season and can inch into the wet season depending on where you are. March and April are more about where to visit rather than when to visit, with the different climates across Thailand presenting various opportunities, from jungle trekking to pristine beaches.
The temperatures begin to drop around October and November, but the rains still fall across the country, especially around the Gulf Coast. The dry season generally hits by mid-October, making the remainder of the month and all of November a fantastic time to experience the jungles, coastlines, and cultural heritage.
Low Season: August • September
August and September are part of the wet season across Thailand, but the rain's impact depends on where you are as opposed to when you visit.
The showers can vary from hard downpours to intermittent droplets throughout the day, but generally, you can still enjoy a number of cultural experiences in Thailand’s famous destinations, rain or shine.