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At a glance
| Dry season | November – April, the most reliable window |
|---|---|
| Rainy season | May – October, wetter but quieter and cheaper |
| Peak crowds & prices | December – February |
| Satellite island closure | Koh Rok & Koh Ha closed mid-May to November |
| Hottest months | March – April, before the rains arrive |
| Best value | The rainy months and shoulder weeks, if you can accept some showers |
The year at a glance
Tap or hover a month. Colour shows how good it is for a trip, bar height shows how much it rains.
Bar height = average monthly rainfall. Crowds and prices: Quiet and cheaper · In between · Busiest and priciest
January
Best weatherReliably dry-season conditions with calm seas, and still busy.
- Daily high 32.9° / low 21.6°
- Rain 32 mm · 5.3 rainy days
- Busiest and priciest
What is open and when
High season: busiest and priciest (December to February)
Koh Rok and Koh Haa open (closed from mid-May to November, dates set each year by the park)
Passenger ferries mainly running (roughly November to April)
Temperatures and rainfall: Krabi climate data 1981 to 2010 (mean daily maximum and minimum, average monthly rainfall and rainy days), the nearest published series for Koh Lanta. Individual years vary; treat every month as a tendency, not a forecast. Levels and crowds follow our own month-by-month notes.
Wikipedia: Krabi (climate data 1981-2010) · Thai Meteorological Department
Dry season (November – April): the safe choice
This is Koh Lanta's high season and the most dependable time to visit: long stretches of sun, calm seas, and every beach, tour and boat trip running on its normal schedule. December through February is also peak season. Expect the highest accommodation prices and the busiest beaches by local standards (still far calmer than Phuket). November and April are a good middle ground: still dry season weather, but a little quieter and often cheaper than the December–February peak.
Rainy season (May – October): quieter, cheaper, with trade-offs
Rain doesn't mean the island shuts down. Expect a mix of sunny mornings and afternoon downpours rather than constant rain, plus noticeably lower prices on tours and hotels . The main trade-off: Koh Rok and Koh Ha, two of the best snorkeling day trips near Koh Lanta, are officially closed from mid-May to November (dates set each year by the park) as part of Mu Ko Lanta National Park's seasonal marine protection. Plan an alternative day trip if you're visiting in this window. Seas can also be rougher, which affects some boat-based tours more than beach time itself.
Shoulder months: April–May and October–November
Late April into May and October into November sit right at the season transition, weather can go either way, but you'll often find lower prices than peak dry season with a reasonable chance of good conditions. If your travel dates are flexible, these weeks are worth watching closely rather than avoiding outright.
What rainy season actually feels like day to day
For a fuller picture of what to expect if you do travel between May and October, see our dedicated guide: Koh Lanta in the rainy season.
Weather by month
For a month-by-month breakdown of temperatures, rainfall and what to expect, see Koh Lanta weather by month.
Match the month to your trip
Use this as a starting point, then check the forecast closer to your dates. Weather is never guaranteed on a tropical island.
| If you want | Aim for | Keep in mind |
|---|---|---|
| The most reliable beach weather | December to February | Highest prices and the busiest beaches; book ahead |
| Good weather with fewer crowds | November or April | April is hot; November can still see late rain |
| Koh Rok and Koh Ha snorkelling | November to mid-May | Both are closed from mid-May to November (dates set each year by the park) |
| The lowest prices | May to September | Rougher seas, some closures and a chance of rain on any day |
| A flexible, low-cost trip | Shoulder weeks | Weather can go either way, so keep plans loose |
When to book
For December to February, book flights and beachfront rooms well ahead, particularly in Kantiang Bay and on Long Beach. In the rainy season you can usually book much closer to your dates, but some smaller guesthouses close, so check that your chosen property is open. See where to stay for the area-by-area picture. If you are still choosing a month for Thailand as a whole, Thailand Voyager's when-to-go guide compares the seasons region by region.
Tours that work well in any season
See all tours
Most bookedFrom US$24Ko Lanta: Half-Day Mangrove Kayaking Tour with Lunch
- 1,089 reviews at 4.7★: the island's most-reviewed mangrove tour
- Half-day kayak through the Thung Yee Peng mangrove tunnels, lunch included
Snorkeling pickFrom US$47Ko Lanta: Koh Rok & Koh Haa Snorkel Tour with Lunch Buffet
- 4.7★ from 650 reviews
- Snorkel at Koh Rok and Koh Haa, two of the best reef spots near Koh Lanta, only runs outside the mid-May to November closure
Reference guides
Frequently asked questions
December to February gives the most reliable dry, sunny weather, though it's also the busiest and most expensive stretch. November and April offer similar weather with fewer crowds.
See where to stayIt's workable: expect mixed sun and afternoon showers rather than constant rain, lower prices, and Koh Rok/Koh Ha closed from mid-May to November (dates set each year by the park).
See what to expectBoth are closed to visitors from mid-May to November (dates set each year by the park) as part of Mu Ko Lanta National Park's seasonal marine protection measures.
See the closure datesYes, it is still dry season and often quieter than the peak months, but it is the hottest and most humid part of the year, and the first rains can arrive late in the month.
See weather by monthIt can be a good choice if you want low prices and quiet beaches and can accept showers, rougher seas and some closures. Have indoor plans for the wettest days.
Compare seasonsWeather and closure dates are typical patterns, not guarantees. Check current conditions before booking.