Thailand in March: Weather, Crowds & What to Expect

Northern Thailand (Chiang Mai, Chiang Rai, Golden Triangle, Pai)

Late March brings noticeably hotter afternoons - often above 30°C in Chiang Mai - and the hills dry out; waterfalls are reduced but the terrain is excellent for mountain biking before the main rains. Songkran preparations heat up here: expect crowds and water-splashing around Tha Phae Gate mid-April, which overlaps with March’s drying trend and rising humidity. Carry light, breathable clothing and a small waterproof pack for sudden car-park sprinklings as locals start early water fights.

Northeastern Thailand (Isan: Ubon Ratchathani, Khon Kaen, Udon Thani, Nakhon Ratchasima)

Late March heats up noticeably; daytime temperatures often reach the mid-30s°C in Nakhon Ratchasima and Khon Kaen, making early-morning activities preferable. Songkran crowding begins as locals prepare for the nationwide water festival in April; safaris to Khao Yai should be planned for cooler parts of the day. Hydration and lightweight clothing are essential - side-trips to air-conditioned museums or caves become welcome retreats.

Central Plains & Bangkok (Bangkok, Ayutthaya, Kanchanaburi)

Late March shifts the mood toward heat and humidity as temperatures climb into the low 30s°C across Bangkok and Ayutthaya, making mid-day outdoor sightseeing tiring. Songkran preparations intensify and the city becomes lively and wet in April, but March is a warning that mornings and late afternoons are best for walking tours. Stay hydrated, carry a cooling towel, and expect stronger sun from rooftop temples.

Eastern Seaboard & Gulf Coast (Pattaya, Hua Hin, Koh Chang, Trat coast)

Late March warms noticeably, with daytime highs climbing and water temperatures becoming inviting for swimming and sea activities. Hua Hin’s beaches are popular for kitesurfing and sailing as winds strengthen slightly; Koh Chang begins to see fewer international tourists but more domestic visitors. Bring sun protection and schedule morning boat trips early to avoid afternoon gusts that can make seas choppier.

Gulf Islands (Koh Samui, Koh Phangan, Koh Tao)

Late March warms toward the pre-monsoon peak; sea temperatures are inviting and island trails become dusty rather than muddy, making for good trekking to viewpoints before the rains. Full Moon Party planning begins as crowds swell around Haad Rin; if attending, book transport and lodge well in advance. Expect hotter, more humid days, and carry water for hikes.

Andaman Coast & Phuket Region (Phuket, Krabi, Phi Phi, Khao Lak)

Late March gradually warms as the southwest monsoon starter approaches; days are still mostly dry and sea temperatures climb, making long-tail and speedboat trips attractive. Railay’s cliffs are busy with climbers and trips to Phang Nga Bay are ideal before rains; bring water and sun protection. Expect the odd early afternoon cloudburst at month’s end, but generally solid beach time.