Thailand in March
March is a transition month — the dry high season is still going in the south, but in the north 'burning season' gradually begins, and temperatures start climbing everywhere toward the April-May heat.
Weather by Region
In the south (Phuket, Koh Samui, Krabi) it's still dry and pleasant. In the north (Chiang Mai, Pai, Chiang Rai), agricultural burning season starts — field burning that creates a smoke haze which can hurt air quality, especially toward the end of the month.
Crowds and Prices
Less crowded than January-February, with prices starting to gradually drop from peak season.
Recommended Destinations for March
Who Should Visit
Anyone planning a southern beach trip — still excellent. Anyone sensitive to air quality who's planning the north should check the AQI before traveling and consider pushing the trip to November-February instead.