Best Time to Visit Thailand: Weather by Region and Month

“When is the best time to visit Thailand?” There is no single answer. The country is long, and on the west and east coasts of the peninsula it rains at different times. This article shows when it is dry, hot or wet in each region, and what that means for your planning.

In short

• It is dry in the north and in Bangkok from about November, and on the Andaman Sea (Phuket, Krabi) from December, in each case until about February or March.
• It gets hot from mid-February to mid-May. April is the hottest month.
• The rainy season in the north and in Bangkok runs from about mid-May to mid-October. On the Andaman Sea it rains a lot from May to October and still noticeably in November.
• The Gulf coast works differently: on Koh Samui, October to December are wet, and November is the wettest.
• In the north, smoke from fires can pollute the air in the dry season, especially around Chiang Mai.

The three seasons

The Thai weather service (Thai Meteorological Department, TMD for short) divides the year into three seasons.

1. Cool season (northeast monsoon): about mid-October to mid-February. Officially it counts as “dry and cool”. That is true above all for the north and the centre; in the south it sometimes still rains heavily in these months (see the table).
2. Hot season: about mid-February to mid-May. April is the hottest month, especially in the north and the centre of the country.
3. Rainy season (southwest monsoon): from about mid-May.

These are rules of thumb, not fixed dates. The weather service declares the start of the rainy season afresh each year, as soon as certain conditions are met. In 2026 it began on 15 May. For the north and the centre, the weather service expected rain until about mid-October, and for the east coast in the south until December.

Rainy season does not mean it rains all day. You should still not underestimate it. From May to October in particular, widespread flooding and landslides are frequent.

Weather by month for every place

What the figures mean for you

North (Chiang Mai): From November to February it hardly rains, and the nights are cool. In January the average low is around 15 °C, so a jacket for the evening belongs in your luggage. In March and April it gets very hot, at 35 to 37 °C during the day. It rains most in August and September.

Centre (Bangkok): It is always hot here, with highs above 30 °C in every month. It is driest from December to February and wettest in September and October.

Andaman Sea (Phuket, Krabi): January to March are the driest months. From May it gets clearly wetter, and it rains most in September. In November, too, Phuket still gets noticeably more rain than Bangkok.

Gulf coast (Koh Samui): Here it is almost the other way round. From February to September the rain usually stays moderate, but in October, November and December it rains heavily. In the southeast of the peninsula, including Koh Samui, there is heavy rain and the occasional tropical storm from November to January.

Rules of thumb for planning

For a tour through the north and the centre, November to February is best. For swimming on the Andaman Sea, December to March is the right time. In the Gulf, that is on Koh Samui, February to September are the better months and October to December the wettest.

If you do not cope well with heat, avoid the north and Bangkok from March to May.

Every month has its own page with all destinations, rain, temperatures and festivals, for example Thailand in January or Thailand in November. The when-to-go overview shows all twelve months and all places at a glance.

You can still travel in the rainy season, but allow for a buffer. In heavy rain, roads are sometimes closed and ferries cancelled.

One more thing about the air: fine particulate pollution in larger cities, especially in Bangkok and Chiang Mai, has risen sharply in recent years. In the dry season from November to April, smoke from fires can also hang in the air in the countryside. If you have problems with your airways or heart, talk to your doctor before the trip.

If you want to stay several months, also read the guide Wintering in Thailand from 50. For roughly what a day on holiday costs, see Costs in Thailand per day. Ready-made routes for two and three weeks are in the guide Thailand tour itineraries.

Important: The figures are long-term averages, and the weather in the year you travel can turn out differently. Shortly before the trip it is worth checking the forecast of the Thai weather service (tmd.go.th) and the advice of the German Federal Foreign Office.