When to Go to Thailand: Cool, Hot and Rainy Seasons

The most popular time to go to Thailand is the cool, dry season, which usually runs from November to February: the air is less humid and the sea is calm in most regions. March to May is the hottest time of year; from May or June to October, monsoon rains occur. However, this picture varies by region: in particular, the rainfall calendar of the Gulf of Thailand, where Koh Samui is, differs from that of the Andaman coast, where Phuket and Krabi are.

Thailand's three seasons

Thailand is a tropical country; even in the period called "winter", it is warm. The year is generally divided into three periods:

1. Cool and dry season (roughly November to February): Humidity is lower and the skies are clearer. Sightseeing in Bangkok is more comfortable, and in the north the mornings and evenings are cool. This is when tourist numbers and demand for accommodation are highest.
2. Hot season (roughly March to May): April in particular is very hot. You need to shift city sightseeing to early morning and late afternoon. It is still a good time for the beach.
3. Rainy season (roughly May/June to October): The rain usually does not last all day; it tends to come in short but heavy downpours in the afternoon or evening. Nature is lush and green, and the crowds thin out. On some days, however, swimming, boat trips and island crossings may be disrupted.

Regional differences

Bangkok and the central region. It follows the general calendar. November to February is the most comfortable period; in the rainy season there may be occasional flooding and traffic.

The north (Chiang Mai, Chiang Rai). In the cool season, nights and mornings in the mountains can be surprisingly cool; take a cardigan. Towards the end of the hot season, air quality can drop in some years because of burning on farmland. If you are going at this time, keep an eye on the current situation.

The Andaman coast (Phuket, Krabi, Phi Phi, Koh Lanta). The best time is usually November to April. From May to October the southwest monsoon can make the sea rough, swimming can become risky on some beaches and access to some small islands may be reduced.

The Gulf of Thailand (Koh Samui, Koh Phangan, Koh Tao). These islands can be relatively drier in the summer months, when the Andaman coast is rainy. The gulf's wettest period is usually from late October to December. So if you are thinking of a beach holiday in summer, the Gulf islands are the more popular choice, and in winter, the Andaman coast.

Festival calendar

Some of Thailand's traditional festivals can add extra colour to your trip, while others may affect your planning.

• Songkran (mid-April): The Thai New Year. It is celebrated across the country with water fights in the streets and is especially lively in Bangkok and Chiang Mai. Be ready to get wet and carry your phone in a waterproof case. Transport gets busy at this time as Thais also travel to their hometowns.
• Loy Krathong (usually November): On the full moon night set by the lunar calendar, small rafts decorated with flowers (krathong) are floated on rivers and lakes. At the same time in Chiang Mai, Yi Peng is celebrated with lanterns released into the sky.
• Chinese New Year (late January or February): Celebrations take place in Bangkok's Chinatown.
• Buddhist holidays: Alcohol sales may be restricted on some religious days. It is a small detail, but it can affect your evening plans.

Festival dates change every year, so check that year's calendar in advance.

Which season suits whom?

• If it is your first trip and you want both city and sea: November to February.
• If you want to avoid crowds and high demand: The beginning or end of the rainy season, prepared for downpours.
• If you want the sea during the summer holidays: The Gulf islands.
• If you are looking for a festival experience: Songkran or Loy Krathong.
• For school or corporate groups: The cool season, with less heat and rain, makes daytime programmes easier.

For a detailed list of what to see in each region, see our article on places to visit in Thailand.

Crowds and demand calendar

Crowds affect your plans as much as the weather. Late December to early January, the New Year period, are the weeks with the most tourists; on popular islands you need to book accommodation and boat trips early. Chinese New Year and European school holidays also increase numbers in some regions. On the other hand, the beginning and end of the rainy season, for example May or October, can offer a quieter and more flexible trip. Remember that some small island businesses and boat services reduce their schedules or take a break in these months.

Small precautions against heat and rain

In every season, sunscreen, a hat, light breathable clothing, mosquito repellent and plenty of water make things easier. In the rainy season, take a light raincoat or a folding umbrella and quick-drying shoes. Do not forget clothes that cover the shoulders and knees for the temples.

We do not have a ready-made catalogue programme for this route; if you would like us to plan one for your group, you can write to us via our contact page.

Frequently asked questions

Which month should you go to Thailand?

In general, November to February is the most popular period. For a beach holiday, however, you should bear in mind that the Andaman coast and the Gulf islands have different calendars.

Can you holiday in Thailand during the rainy season?

Yes. The rain mostly comes in short, heavy downpours and does not last all day. The crowds thin out, but boat trips and island crossings may be disrupted by the weather; keep your plans flexible.

Which island should you choose in Thailand in summer?

Between June and August, the Gulf islands such as Koh Samui, Koh Phangan and Koh Tao are usually drier than the Andaman coast.

When is Songkran and what kind of festival is it?

Songkran is the Thai New Year, celebrated in mid-April. It is marked with water fights in the streets; if you are joining in, be ready to get wet and for crowds.