Covers Phuket, Koh Samui, Koh Lanta, Koh Phi Phi, Bali, Palawan, the Maldives, Mauritius, the Seychelles and Zanzibar, with visa and park rules checked at the source.
UpdatedThis page carries dated prices, schedules or seasonal facts checked on the date above, and that window has now passed. Re-check the sources at the foot of the page before you book.
December is when Thailand's island season swings back to the west. The southwest monsoon has left the Andaman coast, home to Phuket, Phi Phi and Koh Lanta, and the dry, calm months that run to April are starting. Koh Samui, in the Gulf of Thailand, is going the other way: its heaviest rain falls from about mid-October to early December.
Phuket ranks first at 7.79 out of 10, with 85°F (30°C) highs, an 84°F (29°C) sea and 4.3 inches (109 mm) of rain for the month. Samui, the winner from March to October, is last. The cards below give the order; the sections explain the two coasts and how to plan a December trip.
Score = 55% this month's weather + 45% the island's other five factors. How we score
| # | Island | Score | High °F | Sea °F | Rain (in) |
|---|---|---|---|---|---|
| 1 | Phuket | 7.8 | 85 | 84 | 4.3 |
| 2 | Koh Phi Phi | 7.1 | 85 | 84 | 4.3 |
| 3 | Koh Lanta | 7.0 | 85 | 84 | 6.2 |
| 4 | Koh Samui | 6.5 | 82 | 83 | 8.7 |
1Phuket is first in December on both halves of the score. Its December weather score is 8.6, with 85°F highs, an 84°F sea and 4.3 inches of rain, and its year-round scores for things to do (8.5) and value (10) are the best of the four. A well-reviewed Patong 4-star cost $76 for January 13, 2027, the nearest date we priced. Kata and Karon are calm for children again. Book early for holiday weeks.
2Phi Phi is second because it shares Phuket's December weather, an 8.6 with 85°F highs, an 84°F sea and 4.3 inches of rain. Its other scores are the lowest of the four, things to do at 5 and value at 6.8, with the cheapest well-reviewed 4-star at $187 in mid-January. December is a good time to see Maya Bay, open since October 1, at $12 (400 baht) per foreign adult. Stay a night or two, then move on.
3Lanta is third. December starts its recommended season, but its Krabi weather data is wetter than Phuket's: 6.2 inches of rain, for a 7.7 weather score, with 85°F highs and an 84°F sea. It is the family pick, with gentle beaches at Klong Dao and Long Beach and 4-star resorts at $84 in mid-January. There is no airport: fly to Krabi and ride about 24 miles by road and car ferry, or take a dry-season ferry from Phuket or Phi Phi.
4Samui is last in December. The Gulf coast's northeast monsoon gives it its heaviest rain from about mid-October to early December, and its December data shows 8.7 inches of rain, 82°F highs and an 83°F sea, a 6.7 weather score. The east-coast beaches can be choppy and murky in these weeks. Chaweng 4-stars ran $84 in mid-January. If you love Samui, go from March to October, when it ranks first.
In this guide
Each island's December score is 55% its December weather score and 45% its year-round score for beaches, things to do, access, value and crowds. Islands our pages rate as worth it only for some travelers lose 0.4 points. The method is set out in how we score islands.
Weather comes from each island's gateway airport. Phi Phi has none, so it carries Phuket's numbers, which is why the two share a December weather score of 8.6. Lanta's figures come from Krabi airport on the mainland.
Thailand's islands face two seas. On the Andaman coast, the southwest monsoon arrives around mid-May, peaks in September and eases around mid-October, according to the Thai Meteorological Department's seasons as summarized in Wikipedia's Climate of Thailand. December is the first full month of its dry season.
On the Gulf coast, the northeast monsoon brings Samui its heaviest rain from about mid-October to early December, and the southern east coast's rainfall peak runs from November to January. That is why Samui's December weather score is 6.7 and its January score only recovers to 8.4.
In our data, Phuket has the better weather score in November, December and January; Samui has it from February to October. See January for Phuket's best stretch and October for the changeover.
A common December plan is Phuket plus a night on Phi Phi, or Lanta plus a Phi Phi day trip, since dry-season ferries link all three.
We price every island on January 13 and July 14, 2027. January is the nearest date to December and falls in the same high season on the Andaman side. The cheapest well-reviewed hotel rated 4 stars or better on Kayak for January 13, taxes and fees in:
| Island (area) | January 13, 2027 |
|---|---|
| Phuket (Patong) | $76 |
| Koh Phi Phi (Tonsai and Loh Dalum) | $187 |
| Koh Lanta (west coast) | $84 |
| Koh Samui (Chaweng) | $84 |
Holiday weeks may price differently; check your own dates. Add $12 (400 baht) per foreign adult at Maya Bay if your tour does not include it, and about $21 (700 baht) one way for one operator's Phuket to Phi Phi speedboat.
No US airport flies nonstop to Phuket, Krabi or Samui. Phuket connects through Bangkok, Singapore, Doha, Dubai, Istanbul, Seoul, Hong Kong and Taipei. For Lanta, fly to Krabi and continue about 24 miles (38 km) by road and car ferry.
Since September 15, 2026, US citizens get a 30-day visa-free stay in Thailand, down from 60, with up to 30 more days by application. Your passport needs 6 months of validity, and the free Thailand Digital Arrival Card must be filed within 72 hours before arrival. Our passport rules guide has more, and the world December ranking compares Thailand with the Caribbean and Hawaii.
Lunch and snorkel gear are included; the national park fee is only included if you pick that option. Expect a crowded, fast day; Maya Bay closes for August and September.
Rating as shown on GetYourGuide
Price is per boat, so it suits a group; the park fee (400 THB per adult) and lunch are not included.
Rating as shown on GetYourGuide
Pickup, guide, kayak and lunch are included; calm water, good for beginners.
Rating as shown on GetYourGuide
Booking through these links supports this site at no cost to you. Prices move by date, so we do not print them here; the official prices we checked are in the page above.
Yes, on the Andaman coast. Phuket's December data shows 4.3 inches of rain, 85°F highs and an 84°F sea, and it is the start of the dry season that runs to April. Koh Samui on the Gulf coast is still wet.
It is the weakest of the four this month. Samui's heaviest rain usually falls from mid-October to early December, and its December data shows 8.7 inches of rain. Late December is better than early December, but Phuket is the safer choice.
Phuket for weather and things to do: 4.3 inches of rain against 6.2 in Lanta's Krabi data. Lanta for quiet beaches and young children, at the start of its recommended season.
Yes. It closes only from August 1 to September 30, plus occasional rough-weather days. Foreign adults pay $12 (400 baht), and swimming is limited to a marked area.
About 84°F (29°C) in our data, with daytime highs around 85°F (30°C).
Further reading
