Thailand in December: Weather, Where to Go and What to Expect (2026)

December is the start of Thailand’s cool, dry season, and for most travelers it’s the best month of the year for weather. The north is cool at night, Bangkok is comfortable, and the Andaman coast around Phuket and Krabi is in its dry season. The exception is the Gulf coast of the south, where Koh Samui, Koh Phangan and Koh Tao can still be wet. It’s also high season, so crowds and prices are at their highest.

The weather in December, by region

The Thai Meteorological Department defines the winter season as running from mid-October to mid-February, and it names December and January as the coldest months of the year. It grades the cold by the daily minimum: very cold below 8.0 °C, cold from 8.0 to 15.9 °C, and cool from 16.0 to 22.9 °C. Here’s how that looks on the ground.

The north: Chiang Mai, Chiang Rai and the mountains

This is where the cool air is felt most. Days are warm and clear, and nights and early mornings are cool. On the highest mountains in the north and northeast the temperature can even fall below freezing, according to the department. Bring a light jacket for evenings, and a warmer layer if you plan to go up a mountain at dawn. See our Chiang Mai itinerary and Chiang Rai.

Bangkok

The city is cooler than at any other time of year, though afternoons are still warm. For the coldest period this winter the weather service expects morning lows of 19 to 21 °C in Bangkok and 18 to 20 °C in the surrounding area. See our things to do in Bangkok.

The Andaman coast: Phuket, Krabi and Khao Lak

December falls inside the dry season for this coast, which our guides put at November to April, so it’s the main beach choice for the month. See our guides to Phuket and Krabi.

The Gulf coast: Koh Samui, Koh Phangan and Koh Tao

The east side of the south is under the northeast monsoon, and the weather department says its rain often lasts through December and can sometimes be heavy enough to cause floods. That’s why many visitors choose the Andaman side in December and keep the Gulf islands for later in the year. See Koh Samui, Koh Tao and our Koh Samui vs Phuket guide.

What the 2026 forecast says

On 14 October 2026 Thai press reported the weather department’s outlook for the 2026-27 winter. It’s expected to start about a week later than usual and end around mid-February 2027, and to be milder than average. The average minimum for upper Thailand is forecast at 22.0 to 23.0 °C, against a normal of 19.9 °C and 19.6 °C last year. The coldest period should fall between late December and early February, with lows of about 10 to 12 °C in the upper north and northeast. The department linked the mild season to El Niño, which it expects to strengthen towards the end of 2026.

What’s on in December

• 5 December and 10 December. The King Bhumibol memorial birthday, which is also Father’s Day, and Constitution Day, both Thai public holidays.
• Christmas. Not a Thai public holiday, but hotels and malls decorate heavily. See our Christmas in Thailand guide.
• New Year’s Eve. 31 December is a public holiday, with countdown events across Bangkok.
• Loy Krathong. In 2026 it falls on Tuesday 24 November, before December, so if it’s a priority for your trip, come at the end of November.

Crowds and booking

The Christmas and New Year weeks are typically the busiest of the year, with the highest hotel prices and the fewest rooms. Book flights, hotels and any internal flights early, especially for Phuket and Krabi. If you can, travel in the first half of December, before the holiday rush. For a full year view, see our Thailand month by month guide and our best time to visit Thailand page.

A simple December route

1. Three nights in Bangkok.
2. Three nights in Chiang Mai, for the cool mornings and temples.
3. Four to five nights on the Andaman coast, at Phuket, Krabi or Khao Lak.

For the full routes, see our Thailand itinerary for 8, 10 and 14 days. Remember that Americans can stay visa-free for 30 days; see our Thailand visa guide.

Planning it with My Way Travel

We plan private trips in Thailand with a private guide and driver, hotels chosen for the location and the crowds, and internal flights booked around the holiday weeks. My Way Travel is rated 4.8 to 5.0 on Tripadvisor across its listings in Vietnam, Thailand, Cambodia, Spain, Germany and the United States, with more than 3,000 reviews in total. Have a look at our Thailand tours or tell us your dates.

Sources (read in Thai): the Thai Meteorological Department’s climate pages; Naewna on the 2026-27 winter outlook; Thai press on the 2026 Loy Krathong date. Last checked November 2026.

Thailand in December: FAQ

What is the weather like in Thailand in December?

Cool and dry across most of the country, with the coldest nights in the north. The Gulf islands of Samui, Phangan and Tao can still be rainy.

Is December a good time to visit Thailand?

Yes, it has the best weather for most regions, but it’s also high season, with the highest prices and the busiest weeks from Christmas to New Year.

How cold does it get in Thailand in December?

Bangkok mornings of 19 to 21 °C are forecast for the coldest period this winter, and lows of about 10 to 12 °C in the upper north and northeast.

Which beaches are best in December?

The Andaman coast, around Phuket, Krabi and Khao Lak. The Gulf coast around Koh Samui has more rain until the end of the year.

When is Loy Krathong in 2026?

Tuesday 24 November 2026, so it falls just before December.

Is Thailand crowded at Christmas and New Year?

Yes. The Christmas and New Year weeks are typically the busiest, so book early.

Photo: Paktaotik123456, Wikimedia Commons, CC BY-SA 4.0. Huai Nam Dang National Park, Chiang Mai, December 2025.