The best time to visit Koh Lanta is the dry high season from November to April, when the Andaman is calm and every beach bar, dive centre and boat tour is open. Want the same island with half the crowds and half the prices? Aim for February to March, or take your chances in the quiet green season.
Koh Lanta, on Thailand’s Andaman coast in Krabi, lives and dies by the monsoon. Time it right and you get long west-facing beaches, world-class diving at Koh Haa and a laid-back Old Town. Time it wrong and half the bungalows are shuttered and the boats aren’t running. Here is the year month by month, and when to book.
The Short Answer: Koh Lanta’s Two Seasons
Koh Lanta has two clear seasons and almost no middle ground:
- High season (November to April): dry, sunny, calm sea, everything open, higher prices and more people.
- Green season (May to October): the southwest monsoon brings rain and swell, prices crash, and a chunk of the island quietly closes down.
Koh Lanta Weather Month by Month (2026)
Temperatures barely move all year; rain, sea and crowds change everything. Price is relative: 1 cheapest, 5 peak.
| Month | Avg high | Rain | Sea | Crowds | Price |
|---|---|---|---|---|---|
| January | 32°C | Very low | Calm & clear | Busy | 5 |
| February | 33°C | Very low | Calm & clear | Moderate | 4 |
| March | 34°C | Low | Calm | Moderate | 4 |
| April | 34°C | Rising | Warm, calm | Quieter | 3 |
| May | 33°C | Frequent | Getting choppy | Quiet | 2 |
| June | 32°C | Frequent | Choppy | Very quiet | 1 |
| July | 32°C | Frequent | Choppy | Very quiet | 2 |
| August | 32°C | Frequent | Choppy | Very quiet | 2 |
| September | 31°C | Wettest | Rough | Very quiet | 1 |
| October | 31°C | Wettest | Rough, then easing | Very quiet | 1 |
| November | 31°C | Easing | Settling | Building | 3 |
| December | 31°C | Low | Calm & clear | Very busy | 5 |
High Season: November to April (The Safe Bet)
This is peak Lanta. Rain is rare, humidity is manageable, and the Andaman turns flat, glassy turquoise. Every beach from Long Beach (Phra Ae) to Klong Khong, Klong Nin and Kantiang Bay is open, dive centres run daily, and the island tours and boat trips all operate.
High season has three moods:
- December to early January (peak of peak): Christmas and New Year. Beautiful weather, but the busiest and priciest window of the year.
- February to March (the sweet spot): still dry, sunny and calm, but crowds have thinned and rates ease. For most travellers, the best time to visit.
- April (hot and lively): the hottest, most humid stretch before the rains, and Songkran (Thai New Year, 13 to 15 April) water-fight season.
Popular activities on Koh Lanta
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Green Season: May to October (Cheap, Quiet, Wet)
The southwest monsoon runs May to October. Do not picture endless grey: expect hot mornings, a heavy afternoon downpour, then clearing skies. The jungle goes electric green, the Khao Mai Kaew waterfalls flow, and the beaches empty out.
The catch is the sea. Swell hits the exposed west coast, swimming is less pleasant, and far sites like Koh Rok and Koh Haa largely close June to September. September and October are the wettest, least predictable months.
What you buy is space and value: room rates fall 40 to 60 percent and beaches feel almost private. Great if you want a cheap, slow escape and can roll with the weather; not if you need daily boat trips and flat water.
When Things Close (And What Stays Open)
The part most weather guides skip. Roughly May to October:
| What | High season (Nov-Apr) | Green season (May-Oct) |
|---|---|---|
| Beach bars & west-coast restaurants | Nearly all open | Many closed |
| Dive centres & far reef trips | Full schedule | Reduced or paused |
| 4 Islands & Koh Rok boat tours | Daily | Weather-dependent, often none |
| Saladan & Old Town shops | Open | Open |
| Scooter & car rental | Open | Open |
| Food delivery & local eateries | Open | Open |
The upside: everyday essentials never stop. You can still order food delivery on Koh Lanta from town restaurants open all year, sort out airport transfers and getting around, and rent a scooter for the quiet south. The island doesn’t vanish in low season, it just gets sleepy.
Cheapest Months to Visit Koh Lanta
If budget drives your trip, rough 2026 guide prices per night:
| Period | Simple bungalow / night | Scooter / day | Notes |
|---|---|---|---|
| Dec - Jan (peak) | 1,500 - 3,000 THB | 250 THB | Book well ahead |
| Feb - Mar | 1,200 - 2,200 THB | 220 THB | Best weather-to-price ratio |
| Apr & Nov (shoulder) | 800 - 1,500 THB | 200 THB | Good value, mostly open |
| May - Oct (green) | 500 - 900 THB | 200 THB | Cheapest, weekly deals |
The genuine cheapest months are June, September and October; the smartest value play is the April or November shoulder, near-high-season weather without December prices.
Festivals Worth Timing Around
Songkran (13-15 April) closes the high season with friendly water fights in Saladan and Old Town. Loy Krathong (usually November) floats lantern baskets out to sea just as high season begins, and the Lanta Lanta Festival (typically March) brings culture and food to Old Town. Chinese New Year (Jan/Feb) also nudges prices up briefly.
So When Should You Actually Go?
Best weather: December to March. Best value with good weather: the April and November shoulder. Best for diving and island tours: November to April, when Koh Haa and Koh Rok run. Cheapest and quietest: June, September and October, if you pack a rain jacket and stay flexible.
For what fills those days, see the 20 best things to do on Koh Lanta and the 4 Islands Tour guide. Torn between islands? The Koh Tao vs Koh Lanta comparison lays out who each one suits.
Getting Around Whenever You Visit
Koh Lanta is long and thin, so you will want wheels. A rented scooter is the classic way to hop between beaches, around 200 THB a day. Not driving, or landing late from Krabi airport? Book a taxi or airport transfer through KOHME. The app also bundles food delivery at local prices, activities and rides into one place, handy in green season for finding what is open. Diving? The Koh Lanta diving guide covers seasons, sites and costs.
Frequently Asked Questions
When is the best time to visit Koh Lanta?
November to April, the dry high season, when the sea is calm and everything is open. February and March are the sweet spot: sunshine with fewer crowds and lower prices than the Christmas and New Year peak.
What are the cheapest months to visit Koh Lanta?
May, June, September and October. Accommodation drops 40 to 60 percent versus December and January; the trade-off is more rain and rougher seas.
Is Koh Lanta worth visiting in the green (low) season?
Yes, if you want a quiet, cheap island and can stay flexible. Rain comes in short bursts and beaches are almost empty, but some restaurants and dive centres close and boat trips depend on the weather.
Does Koh Lanta shut down in the low season?
Not entirely, but many west-coast beach bars, restaurants and dive centres close from around May to October. Saladan and Old Town stay open year-round for food, shops and scooters.
When is the rainy season on Koh Lanta?
The southwest monsoon runs roughly May to October, with September and October the wettest. Rain usually falls as short downpours followed by sunshine, but the sea gets choppy.
Is the sea calm enough for diving and island tours year-round?
The calmest, clearest water is November to April, prime time for the 4 Islands Tour, Koh Rok and Koh Haa diving. In the June to September monsoon many boats stop, so plan diving for high season.
Activities on Koh Lanta
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Related Links
- Koh Lanta on KOHME - food, activities & scooter rental
- 20 best things to do on Koh Lanta
- 4 Islands Tour guide
- KOHME Blog - more island guides
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