Thailand in March: what to expect

March is the hinge between Thailand's cool season and its hot season. The dry northeast monsoon has faded, rain is scarce almost everywhere, and temperatures climb week by week. Bangkok and the central plains sit in the mid-30s °C by late March, and the Andaman and Gulf coasts are warm but still comfortable for swimming, with calm seas before the southwest monsoon arrives in May.

The exception is the north. February to April is the burning season, when agricultural fires and forest smoke push Chiang Mai and Chiang Rai air quality among the worst in Asia. Temperatures there are pleasant, but the haze is the reason the parent country guide flags March as caution rather than go.

March sits in the shoulder between the December–February peak and the low season that starts in May. Island and beach beds are easier to find than in January, and rates on the Andaman coast usually soften after mid-February, though Phuket and Krabi still charge high-season money through the month.

The north is the cheapest part of the country in March precisely because the haze keeps some travellers away. Bangkok is steady year-round: business travel keeps hotels busy on weekdays, and weekend rates rise. Book beach accommodation a few weeks ahead if your dates fall near a full moon or a Thai holiday.

March has no nationwide festival on the scale of Songkran in April or Loy Krathong in November. The one fixed point is Makha Bucha, a Buddhist holiday that falls on the full moon of the third lunar month — in February or March depending on the year. Temples fill in the evening with candlelit processions, and alcohol sales are banned for the full day, including in bars and restaurants.

Check the exact date for your year before you plan around it, and note that the ban applies nationwide, not just at temples. Beyond that, March is a month of ordinary local life: temple fairs, weekend markets and the run-up to the April heat.

Spend March on a coast. The Andaman side — Phuket, Krabi, Koh Lanta, Khao Lak — is in its dry window with calm water and no red flags, and the Similan and Surin island parks are still open before the monsoon closes them. The Gulf islands of Samui, Phangan and Tao run on the opposite rhythm and are dry and calm from February through September, so they work equally well.

Bangkok is fine for a few days if you plan around the heat: temples and markets early, air-conditioned museums and malls in the afternoon. Kanchanaburi and Ayutthaya are day-trip friendly but exposed, so start at opening time. In the north, Chiang Mai and Chiang Rai are best left to another month unless the air quality happens to be clear when you travel.

Pack for heat and sun, not rain. Light, loose clothing in cotton or linen, a hat, sunglasses and high-factor sunscreen cover most of the month; a light long-sleeve layer helps in air-conditioned buses, trains and malls. Comfortable sandals or breathable shoes work for temple visits, where shoulders and knees need covering.

Add a refillable water bottle, oral rehydration salts for the hottest days, and a mask if you are going north and the AQI is poor. A small umbrella is useful for sun as much as for the rare shower. See the full Thailand packing list for the rest.

February is cooler and drier but busier and more expensive, and the northern haze is already building. April is the hottest month of the year and brings Songkran on 13–15 April, which soaks the whole country and fills transport out of Bangkok. May turns wet on the Andaman side while the Gulf islands stay dry.

If your dates are flexible and you want the north, aim for November to February. If you want beaches at lower prices, May is cheaper but the west coast gets rough.