December · Thailand weather
Thailand in December: Weather, What to Expect & Where to Go
Updated
December is the most popular month of the year. The weather is reliably excellent — cool in the north, comfortable in Bangkok, dry on the Andaman. The Gulf islands are still wet early in the month but recovering. Expect peak prices, packed hotels, and a strong Christmas/NYE surge.
Best region
North
Chiang Mai is at its best — cool, dry, clear. The mountains around Pai and Mae Hong Son are stunning.
Avoid
Gulf
Samui is still in its wet pattern early in the month, drying out toward NYE.
Good for
Cool-season highlights, NYE in Bangkok, family trips
December weather, region by region
Average temperatures and rainfall across Thailand's five climate regions in December. Tap the climate map on the homepage for an interactive month-by-month view.
| Region | Avg temp | Rainfall | Visit rating |
|---|---|---|---|
North Chiang Mai | 22°C | 15mm | Great |
Northeast Nakhon Ratchasima (Korat) | 24°C | 5mm | Great |
Central Bangkok | 27°C | 10mm | Great |
Andaman Phuket | 28°C | 70mm | Great |
Gulf Koh Samui | 27°C | 190mm | Good |
City spotlights
One city per region — what December actually feels like on the ground, and what to do or skip.
North
Chiang Mai
By the numbers
Chiang Mai averages 22°C — daytime highs around 28°C, nights dropping to 14–16°C. Just 15mm of rain across 1–2 days. Air is at its annual cleanest.
Cool, dry, and clear. Sunrise temperatures around Pai can dip into single digits — possibly the only time of year you'll need a real jacket in Thailand.
Cool mornings, warm afternoons, almost no rain. Bring layers for sunrise — early-morning temperatures can dip into single digits in the hills around Pai.
Year-round climate
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Northeast
Nakhon Ratchasima (Korat)
By the numbers
Korat averages 24°C with daytime highs of 30°C and cool nights of 16°C. Just 5mm of rain across 1 day. Khao Yai mornings can hit single digits.
The Korat plateau is at its photogenic best — gold grasslands, morning mist, brilliant blue skies.
Cool, dry, and beautiful. The Korat plateau is at its photogenic best — Khao Yai's grasslands turn gold and Phimai sees morning mist. Bring a real jacket — nights can hit single digits.
Year-round climate
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Central
Bangkok
By the numbers
Bangkok averages 27°C — daytime highs around 32°C, nights around 22°C. Around 10mm of rain across 1–2 days. Humidity at its annual low of 55%.
Peak Bangkok weather. NYE on the Chao Phraya is one of the best fireworks displays in the region.
Peak Bangkok weather. NYE on the Chao Phraya is one of the best fireworks displays in the region — book river-view dinners weeks ahead.
Year-round climate
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Andaman
Phuket
By the numbers
Phuket averages 28°C with around 70mm of rain across 5–6 days. Sea visibility 20–30m. Peak season in full swing.
Peak season. Beaches packed, prices at their highest, but weather reliable.
Peak season in full swing. Beaches are packed, prices are at their highest, but the weather is reliable.
Year-round climate
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Gulf
Koh Samui
By the numbers
Koh Samui averages 27°C with around 190mm of rain across 14 days, easing toward NYE. Sea temperature 28°C.
Drying out through the month. Early December still risky; late December and NYE are usually fine.
Drying out through the month. Early December still risky; late December and NYE are usually fine.
Year-round climate
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Events & festivals in December
Father's Day (5 December)
King Bhumibol's birthday. Bangkok lights up around Sanam Luang and the Grand Palace.
Christmas / New Year surge
Hotel rates can triple on the islands. Book months ahead, or wait until mid-January for the post-NYE lull.
Where to actually go
Ten days in December
- 3days
Bangkok
Peak weather. Pre-NYE, the city is buzzing.
Train · 13h overnight sleeperBook on 12Go - 3days
Chiang Mai
Cool mornings, clear mountains. Bring a real jacket for early starts.
Flight · ~3h with layoverBook on 12Go - 4days
Phuket
Peak Andaman season. Packed beaches, peak prices, but reliable weather.
Skip Koh Samui until at least the second half of the month — early December is still in the Gulf's wet pattern. By NYE, it's usually back to reliable.
Sea conditions in December
Thailand has two coastlines on opposite monsoon calendars. Here's what each looks like this month for swimming, diving, and boat trips.
Andaman coast — Phuket, Krabi, Phi Phi
Peak season. Sea visibility 20–30m, calm seas, all dive operators running, Similan live-aboards at peak.
Gulf coast — Samui, Phangan, Tao
Improving through the month. Early December still wet and choppy; late December usually back to reliable. By NYE, Koh Tao diving is running again.
How crowded is Thailand in December?
Most popular month of the year. Christmas/NYE pushes hotel rates to triple their normal levels on the islands. Book Phuket, Krabi, and Chiang Mai 3–4 months ahead, or wait until mid-January for the post-NYE lull. Bangkok is more flexible.
What to pack for Thailand in December
- Light layers — T-shirts plus warmer evening clothes
- A proper jacket or fleece for Chiang Mai, Pai, and Khao Yai mornings
- Modest temple-visit outfit
- Sunglasses and SPF 30+ for the Andaman side
- Smart-casual evening clothes if you're doing NYE on the river
December nights in the mountains can hit single digits — Pai sometimes sees 5–8°C before sunrise. Pack a real jacket if you're heading north, not just a thin layer.
Thailand in December — common questions
Is December a good time to visit Thailand?
Yes — December is one of the best months, full stop. Weather is reliably excellent across the country (Bangkok at its lowest humidity of the year, Chiang Mai cool and clear, Andaman at peak), and the cultural calendar is strong with NYE on the Chao Phraya. The only caveats are crowds, peak pricing, and lingering rain on the Gulf islands in the first half of the month.
Is December rainy season in Thailand?
Mostly no. Bangkok, the north, and the Andaman coast are all in their cool-dry season — Bangkok sees just 10mm of rain across 1–2 days for the entire month. The Gulf coast is still in its wet season early in December but dries out toward NYE.
How cold does Chiang Mai get in December?
Chiang Mai averages 22°C in December — its coolest month. Daytime highs are around 28°C, but overnight lows drop to 14–16°C in the city and into single digits in the hills around Pai and Mae Hong Son. Sunrise temperatures around 8°C are common — bring a real jacket if you're heading north.
Should I book Phuket far in advance for December?
Yes — December is peak season for the Andaman coast. Hotel rates triple for Christmas week and NYE compared to October. Book accommodation 3–4 months ahead for guaranteed availability and 5–6 months ahead for the best prices. Mid-month dates (December 5–18) are slightly easier than the holiday weeks.
When does Koh Samui's weather improve in December?
Usually around mid-December. The Gulf wet season peaks in November and tapers through early December — the first two weeks of December are still risky, with regular rain and choppy seas. By December 20 onwards, conditions are typically back to reliable, with calm seas and clearer skies by NYE.
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Thailand in November
Yi Peng lanterns in Chiang Mai, Andaman beaches, Bangkok in full swing
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Thailand in January
Cool mornings in Chiang Mai, beach weather on the Andaman side
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