Thailand in April: what to expect

April is the tail of the dry season and the peak of the heat. Bangkok and central Thailand regularly reach the high 30s °C, and the heat index climbs higher in the afternoon. Rain is limited — the southwest monsoon usually arrives in May — but the odd pre-monsoon thunderstorm can drop a fast, heavy shower, mostly late in the day.

The north (Chiang Mai, Chiang Rai, Pai) is the problem area. The burning season runs February to April, and April is often the worst month for air quality, with AQI readings among the highest in Asia. Check AQI before booking anything in the north this month.

The coasts behave differently. The Andaman side (Phuket, Krabi, Koh Lanta) is still in its dry window, though seas begin to build late in the month. The Gulf islands (Koh Samui, Koh Phangan, Koh Tao) are in their best stretch — dry, calm and clear through September.

April splits into two very different weeks. Before Songkran, crowds are moderate and prices normal for the shoulder season. From about 10 to 16 April, the country moves: Bangkok empties toward the provinces, buses and trains sell out days ahead, and island ferries fill. Hotel rates on the islands and in Chiang Mai spike for the holiday.

If you are not here for Songkran, the second half of the month is quieter and cheaper, though still hot. Book long-distance transport before you arrive if your dates touch the festival.

Songkran, the Thai New Year, runs 13–15 April nationwide and is the month's defining event. Expect water fights in every city, many shops and offices closed, and heavy demand on transport out of Bangkok. Phones, passports and electronics need waterproof protection. Some temples hold quieter merit-making ceremonies if you want the tradition without the soaking.

Note that Buddhist holidays can carry a nationwide ban on alcohol sales for the day; check locally if that matters to your plans.

Head for the water. The Gulf islands are the strongest choice: dry, calm and in their best season. The Andaman coast also works, though seas start to build toward May. Bangkok is manageable if you plan around the heat — early mornings, air-conditioned breaks, and evenings out.

Skip the north this month unless you have checked the air quality and it is acceptable to you. Chiang Mai and Pai are at their haziest and hottest. If you want the north, save it for November to February.

Pack for heat and water. Light, quick-dry clothing, a hat, high-factor sunscreen and refillable water are essentials. If your trip overlaps Songkran, add a dry bag for phone and passport, and expect to be wet from the moment you step outside.

March is slightly cooler and drier in the south but the northern haze is already bad. May brings the first monsoon rains and lower prices, with the Gulf islands still the pick. February is one of the best months overall — dry, cooler and before the worst of the burning season.