Koh Lanta Weather by Month: Seasons and What to Expect

Dry season: November to April

• November: The transition into the dry season. Weather can still be mixed early in the month, with conditions generally improving and prices often below peak.
• December: Typically among the sunniest and calmest months, and the start of peak season, so expect the busiest and most expensive period around the holidays.
• January: Reliably dry-season conditions with calm seas, and still busy.
• February: Much like January: settled weather and strong demand for rooms and boat trips.
• March: Still dry and increasingly hot; sunshine is dependable and crowds ease slightly compared with mid-winter.
• April: Often the hottest and most humid part of the year, with the first pre-monsoon showers possible late in the month.

See the full best-time-to-visit guide

Rainy season: May to October

• May: The monsoon usually sets in. Expect a mix of sun and heavy showers, and note that Koh Rok and Koh Haa close from 16 May.
• June: Wetter and greener, with rougher seas on some days; often good value.
• July: Showers and cloud alternate with bright spells; boat trips can be cancelled by swell.
• August: Similar to July, with the sea often at its choppiest.
• September: Commonly one of the wettest months on the Andaman coast, with long grey spells possible.
• October: Rain is often still heavy early in the month, easing towards its end; Koh Rok and Koh Haa reopen on 15 October.

Read what to expect in the rainy season

How to use this

If reliable sun and calm seas matter most, aim for December to March. If you want lower prices and quieter beaches and can tolerate showers, June and the shoulder weeks either side of the wet season can be good value. The transition months are the hardest to call, so if your dates are flexible, choose them close to travel using a live forecast.

Weather affects boat trips more than beach days: rough seas are what usually cancels an outing. Build a spare day into your plan for any must-do boat trip in the wet months.