Best Time to Visit Thailand: Month by Month, Coast by Coast

For most of Thailand the best time to visit is November to February: dry, sunny and as cool as the country gets. But Thailand has two coasts with opposite monsoons, so the real answer depends on where you are going. Phuket and Krabi are at their best from December to April, while Koh Samui and the Gulf islands are often at their best from January to August.

This guide breaks the year down by region and by month, so you can either pick dates for a place or pick a place for your dates.

Thailand's three seasons in one minute

Thailand's weather follows three broad seasons. Exact timing shifts from year to year, so treat the months below as typical patterns, not guarantees.

• Cool and dry season (roughly November to February): lower humidity, blue skies, comfortable evenings in Bangkok and genuinely cool nights in the northern mountains. This is peak season, with the highest hotel rates.
• Hot season (roughly March to May): temperatures in Bangkok and the central plains regularly pass 35 °C, and April is usually the hottest month. Beaches are still good, especially on the Gulf side.
• Rainy season (roughly June to October): the southwest monsoon brings showers and storms to most of the country. Rain often comes as a heavy afternoon downpour rather than all-day drizzle, but the Andaman Sea gets rough and some boat trips are cancelled.

Region by region

Andaman coast: Phuket, Krabi, Phi Phi, Khao Lak

The west coast is the classic postcard Thailand, and its calendar is simple. December to April brings calm, clear water and the best visibility for snorkelling. From May to October the southwest monsoon pushes waves onto the west-facing beaches, red flags go up at Patong, Kata and Karon, and the sea can be too rough for speedboats.

If island hopping is the reason for your trip, plan it for the dry months. A speedboat day such as our Phi Phi, Maya Bay and Bamboo Island trip from Phuket or the Krabi 4 Islands day trip by longtail boat is at its best when the sea is flat. Two dates worth knowing: the Similan Islands national park usually opens from mid-October to mid-May only, and Maya Bay has in recent years closed for around two months each year, usually August and September, to let the reef recover. Check the current dates before you book.

Gulf of Thailand islands: Koh Samui, Koh Phangan, Koh Tao

The Gulf islands sit in the rain shadow of the southwest monsoon and get their heaviest rain later, typically October to December, when the northeast monsoon arrives. From January to August they are usually dry and sunny, which makes Koh Samui the natural beach choice for a summer holiday when the Andaman side is rough.

Bangkok and central Thailand

Bangkok is a year-round city, but it is far more pleasant from November to February. March to May is very hot and humid, and walking around the Grand Palace at midday in April is hard work. During the rainy season, streets can flood briefly after storms, but temples, markets and river trips still run; just plan indoor time for the afternoon.

Pattaya and the eastern seaboard

Pattaya, two to three hours by road from Bangkok, has weather close to Bangkok's but a little drier. November to March is ideal. The rainy months are rarely a washout, and the short boat ride to Koh Larn runs most of the year in normal conditions.

The north: Chiang Mai and Chiang Rai

The north has the most pronounced cool season. From November to January mornings in the mountains can drop below 10 °C, and the views from Doi Inthanon are at their clearest. Pack a light jacket for an early start on a Doi Inthanon National Park day trip from Chiang Mai.

One warning: from roughly February to April the north has a burning season, when crop and forest fires fill the air with smoke. Air quality in Chiang Mai can be among the worst in the world for days at a time. If you have asthma or are travelling with small children, avoid these months in the north.

Month by month at a glance

Month	Andaman (Phuket, Krabi)	Gulf (Samui)	Bangkok and Pattaya	North (Chiang Mai)
January	Excellent	Good	Excellent	Excellent, cool nights
February	Excellent	Excellent	Very good	Good, smoke starts
March	Very good	Excellent	Hot	Smoky
April	Good, hot	Excellent	Very hot, Songkran	Smoky, hot
May	Monsoon begins	Very good	Hot, first rains	Rains begin
June to August	Rough sea, showers	Very good	Rainy, still workable	Green, rainy
September	Wettest month	Good	Wettest month	Rainy
October	Improving late	Rains start	Rain easing	Improving
November	Very good	Wettest	Very good	Excellent
December	Excellent	Rainy	Excellent	Excellent, cool

Festivals that are worth planning around

• Songkran (13 to 15 April): Thai New Year, celebrated nationwide with water fights in the streets. Great fun, but expect to be soaked, and book transport early because Thais travel home.
• Loy Krathong (November full moon): people float small decorated baskets on rivers and canals. In Chiang Mai it coincides with Yi Peng, when lanterns are released into the sky.
• Chinese New Year (January or February): lively in Bangkok's Chinatown and in Phuket Old Town.
• Vegetarian Festival (usually October): Phuket's best-known festival, with processions and strict vegetarian food stalls across the old town.

Peak, shoulder and green season: what it means for your budget

Peak season runs from about mid-December to February, with the Christmas and New Year weeks the most expensive of the year. Rooms in Phuket and Krabi can cost two or three times what they cost in September. April and May, and October and early November, are the shoulder months: decent weather in most regions and noticeably lower rates.

The rainy season, which the tourism board calls the green season, is the cheapest time to travel. It works well if you combine Bangkok, the north and the Gulf islands, and keep flexible days for boat trips. Families tied to European school holidays in July and August usually do best on Koh Samui or with a city-and-north itinerary rather than on the Andaman coast.

So when should you go?

• First trip, mixing Bangkok, the north and a beach: late November to February.
• Island hopping around Phuket and Krabi: December to April.
• Beach holiday in July or August: Koh Samui, Koh Phangan or Koh Tao.
• Lowest prices: May, June and September, accepting some rain.
• Cool weather and mountains: Chiang Mai from November to January, avoiding the smoke from February.

FAQ

What is the cheapest month to go to Thailand?

Usually September, the wettest month in Bangkok and on the Andaman coast. May and June are also good value. Prices rise again from November and peak over Christmas and New Year.

Is it worth going to Phuket in the rainy season?

It can be, if you want lower prices and do not mind showers. Rain usually comes in bursts, but the sea on the west-facing beaches is often rough, swimming can be dangerous under red flags, and some island boat trips are cancelled at short notice.

When is the best time for Koh Samui?

January to August is usually dry and sunny. The wettest months are typically October to December.

When should I avoid Chiang Mai?

The burning season, roughly February to April, often brings heavy smoke and poor air quality. November to January is the most comfortable time to visit the north.

Can I visit Maya Bay all year?

Not always. In recent years Maya Bay has closed for about two months each year, usually August and September, and swimming in the bay itself is not allowed. Check the national park's current dates before travelling.