Thailand Islands in December: Andaman or Gulf, and Your eSIM
Christmas in Thailand means picking a coast. The Andaman side (Phuket, Krabi, Phi Phi, Lanta, Lipe) is dry; Samui, Phangan and Tao are finishing their wettest months. Here is the calendar, the booking reality and the data plan for island days.
Quick answer: For December, pick the Andaman coast: Phuket, Krabi, Phi Phi, Koh Lanta and Koh Lipe are in their dry season, while Koh Samui, Koh Phangan and Koh Tao on the Gulf side are finishing their wettest stretch, which peaks in November. From January the Gulf islands dry out too, and February suits both coasts. Christmas to New Year is ultra-peak on every island, so book rooms and ferries ahead, and install a travel eSIM at home so tickets, maps and bookings work on the pier.
Key takeaways
- December: Andaman side. It dries out from October, while the Gulf islands are still in their wet months.
- January to February: both coasts work, with the Gulf at its driest and calmest from January.
- Christmas and New Year are ultra-peak. Even island-hoppers who never pre-book say to book this window.
- Ferry days are signal days: save tickets and maps before you board, because coverage comes and goes at sea.
- Thailand-only fixed plans cut off when the data is used, so size up or take unlimited for an island trip.
You booked Koh Samui for Christmas because the photos were perfect, then a friend who lives there tells you November and December are the wet months on the Gulf side. Or you are on the Phi Phi pier at 9am with a ferry QR that will not load, and the boat is boarding. Both problems are easy to avoid if you sort them at home.
The data part takes five minutes: get a Thailand eSIM on fizen.io, install it on home Wi-Fi before the flight, and switch it on at Phuket or Krabi airport. Your ferry tickets, Grab and the hotel's WhatsApp then work from the arrival hall to the last longtail.
Which Thai islands are dry from December to February?
| Month | Andaman: Phuket, Krabi, Phi Phi, Lanta, Lipe | Gulf: Samui, Phangan, Tao |
|---|---|---|
| December | Dry season, calm seas, ultra-peak at Christmas | Still wet; heavy rain possible, seas can be rough |
| January | Dry and busy | Drying out; the coolest, most pleasant month |
| February | Dry, hotter | Dry and calm; one of the best months |
Travel weather guides put Koh Samui's rain at around 445 mm in November with December not far behind, while the Andaman coast dries out and calms down from October. Weather never follows the calendar exactly, so build a spare day into any island-hopping plan.
If your heart is set on the Gulf over Christmas, go anyway with flexible bookings and an indoor plan, or push the Gulf leg to January and spend Christmas on the Andaman side.
How hard is booking the islands over Christmas and New Year?
- Rooms: the Christmas to New Year stretch is the priciest of the season, and small islands can sell out. Book well ahead.
- Ferries and transfers: book the Christmas and New Year crossings in advance, and keep the confirmation as a screenshot as well as in the app.
- Koh Lipe: the van and boat transfer from Hat Yai takes around four hours, which keeps the crowds smaller, but the island still fills on holidays, because Malaysia and Singapore are next door.
- Cash: small islands lean on cash for longtails, food stalls and some guesthouses. Withdraw on the mainland or a big island first.
What people who have done it say
- Book this window, even if you never book. A Thailand destination expert who normally tells island-hoppers to stay flexible said Christmas to New Year is ultra-peak everywhere, and small islands can book out.
- Koh Lipe at New Year is dry and busy. Regulars corrected a poster who feared rain: it is mostly dry and super-high season, and busy with weekend visitors from Malaysia and Singapore.
- On Samui, October to December are the wet months. In a 2024 thread, a long-time poster called January the coolest and driest month, and another warned that even the Gulf crossing can be rough then.
- Plan by late summer. In August 2018, a Samui-based regular told a Koh Lipe New Year planner it was not too early to book, and had just booked her own Christmas room.
Which Thailand eSIM plan fits an island trip?
One option, read from the Fizen catalogue on 2 November 2026: Thailand-only plans run on TrueMove H 4G and 5G. The unlimited plans run from 3 to 30 days at up to 10 Mbps, enough for maps, ferry apps, video calls and photo uploads. The Thailand-only 3 GB and 10 GB plans disconnect once their data is used rather than slowing down. The Asia regional plan, useful if you continue to Malaysia, Vietnam or beyond, uses AIS 5G in Thailand and slows to 128 kbps after its data. Check the eSIM tab in the app or fizen.io/esim for current plans.
| Your island trip | Rough use | Plan that survives it |
|---|---|---|
| Under a week, one island, light use | About 1 GB a day | 10 GB, 7 days |
| Two weeks hopping Phuket, Phi Phi and Lanta | 1.5 to 2 GB a day | Unlimited, 15 days |
| Christmas to mid-January, Andaman then Gulf | 1.5 GB a day or more | Unlimited, 30 days |
These are our estimates. On a ferry day, download offline maps of your next island, screenshot the ticket and hotel booking, and send anything important before the boat leaves. Most Fizen eSIMs cannot be topped up, and more data means a new eSIM, so size it for the whole trip. If something fails on Fizen's side, a real person answers in the in-app chat, and a verified fault gets a free 1-for-1 replacement for the length of the trip. Changed plans? An unused, not-yet-installed eSIM can usually be taken back; eligibility depends on the plan, check Package details or ask chat.
The honest alternative: a True or AIS tourist SIM at the airport, registered with your passport; True's terms cap tourist SIMs at 60 days. It is fair if you do not mind the counter queue after landing. Paying in USDT? The same plans are in the Fizen app. Fizen is building the stablecoin neobank for people on the move: a wallet you own and data in 150+ countries in one app.
Sorted, December looks like this: the Lanta ferry QR opens on the pier, the longtail back from Railay is booked before the cliffs swallow the signal, and New Year's Eve is fireworks over the bay, not a hunt for Wi-Fi.
Frequently asked questions
Which Thai islands are best in December?
The Andaman side: Phuket, Krabi, Phi Phi, Koh Lanta and Koh Lipe. It is dry, while Samui, Phangan and Tao are still in their wet season.
Is Koh Samui rainy in December?
Often, yes. October to December are its wettest months, with November the peak. January is usually cooler and drier.
Do I need to book Thai islands in advance for Christmas?
Yes. Christmas to New Year is ultra-peak, and small islands can sell out.
Does mobile data work on Thai ferries?
Partly. Signal comes and goes at sea, so save tickets and offline maps before boarding.
What happens when a Thailand eSIM runs out of data?
Thailand-only fixed plans disconnect; regional plans slow to 128 kbps. Unlimited avoids both.
Island season, tickets and maps on your phone
Install a Thailand eSIM at home and land in Phuket or Krabi with ferry apps, Grab and hotel chat ready. Pay by card via Stripe (international Visa or Mastercard, Apple Pay, Google Pay), or with USDT on Solana or BNB Chain in the Fizen app. New in the app: a US$10 eSIM credit is waiting in the eSIM tab for new users, taken off the bill automatically at checkout (up to 30% of each plan), no code needed.
Terms and conditions
- Information only. This article is information only, not an offer or sale, and not financial, legal or travel advice. Weather, ferry schedules and prices change; check before you rely on them. Plan details were read from the Fizen catalogue on 2 November 2026; check Package details before you buy.
- For readers in the United States. This is information only, not an offer or sale, and not advice. Fizen products and services are not offered to US Persons.
- Data-only. Travel eSIM plans are data-only and do not include a Thai phone number or SMS. Keep your home SIM active for calls, SMS and bank codes.
- Independent. Fizen is not affiliated with TrueMove H, AIS, any ferry operator or Tripadvisor.
Sources
- Wego, Thailand monsoon season by coast (13 July 2026)
- Tripadvisor Thailand forum, island hopping over Christmas and New Year (2018)
- Tripadvisor Ko Lipe forum, New Year in Ko Lipe (2018)
- Tripadvisor Ko Samui forum, best time for minimal rain (2023 to 2024)
- True and dtac, tourist SIM terms and conditions
- Fizen Docs, 1:1 Trip Guarantee and refunds
Weather pattern checked 2 November 2026 (Wego, July 2026); forum threads 2018 to 2024; True tourist SIM terms read 2 November 2026; Fizen catalogue read 2 November 2026.
