Is December a good time to go to Thailand?

December is one of Thailand's best months to visit if you go at the right time within the month.

The Andaman coast

Phuket, Krabi, Koh Lanta, and Phi Phi are in full high season. The Andaman dry season is firmly established. Beaches are calm, skies are clear, and the Similan Islands are running full liveaboard schedules. Dive visibility reaches 20-25m. Day trips to Phi Phi and Maya Bay run daily.

The first three weeks of December are arguably the best-value window in Phuket's entire year: dry-season conditions without the January-February full-peak prices. December 1-20 gives you beach days that are essentially the same as January at 15-20% lower cost.

Bangkok and the north

December is Bangkok's most comfortable month. Daytime highs are around 32°C and nights around 23°C, with the lowest humidity of the year. Rain is minimal. The catch is the air: PM2.5 haze starts building in December, so check the AQI on bad days. Walking between temples and markets in December is more pleasant than any other month. The Grand Palace, Wat Pho, and the Chao Phraya river piers are all at their most comfortable in the morning cool.

Chiang Mai enters its best period in December. Night temperatures drop to around 17°C in the city and lower in the hill stations, and the peaks can hit single digits on the coldest mornings. Doi Inthanon, Thailand's highest peak, can frost at the top in December in cold years. The hill tribe villages north of Chiang Rai are accessible and at their most photogenic with clear views.

The Gulf coast

Koh Samui and Koh Phangan are transitioning out of their worst months (October-November). Early December can still see unsettled weather on Samui. By mid-December the coast is usually clearing. Koh Tao is no safer: its dive schools stick to sheltered sites with poor visibility until the monsoon ends, usually around Christmas, and Koh Tao ferries and speedboats get cancelled on rough days.

If Gulf islands are the specific plan, book for December 15 onward rather than the start of the month, and leave a spare day around any ferry.

Christmas and New Year

December 24 to January 2 is when Phuket, Bangkok, and Koh Samui run at maximum capacity. Hotels at peak prices (sometimes higher than standard January rates for specific nights). Restaurants require reservations. Ferries sell out. This is fine if you want the atmosphere, but budget and logistics need to be planned well ahead.

The first three weeks of December are completely different from the Christmas week. Knowing this matters.

For the full December picture, see our Thailand in December guide.