Best time to visit Koh Lanta
Ko Lanta has two seasons: a dry, calm high season from about December to April, and a greener, wetter low season from about May to November when the southwest monsoon crosses the Andaman. The figures below are real climate normals — ten years of daily records averaged into a typical year — so you can see exactly how warm, wet and busy each month tends to be.
Dry season vs green season
Local knowledgeThe tourist high season on Ko Lanta runs from around November, when the Andaman calms and the fast boats resume, through to April. In the climate data the rain itself eases a little later: the driest half of the year runs roughly December to April, with February the driest month of all — only about 30mm of rain across 6 days. The driest stretch overall is February, March and January. Through these months daytime highs sit around 32°C, the sea is calm, and the speedboats from Phuket and Phi Phi are running.
The green (low) season runs roughly May to November, when most of the year's rain falls. It builds through the monsoon and peaks in October, the wettest month, with about 336mm across 27 rainy days — with September close behind at about 325mm. The wettest months are October, September and May. The rain usually comes in short heavy bursts, and it stays warm: even in October the mean temperature is about 26.9°C.
Month-by-month climate
Typical year| Month | Mean temp | Avg high | Avg low | Rainfall | Rainy days | Season |
|---|---|---|---|---|---|---|
| January | 27.2°C | 30.4°C | 24.9°C | 74 mm | 10.9 | Dry / high |
| February | 27.8°C | 31.7°C | 25.2°C | 30 mm | 6.3 | Dry / high |
| March | 28.6°C | 32.3°C | 25.8°C | 55 mm | 10.1 | Dry / high |
| April | 28.6°C | 31.4°C | 26.3°C | 130 mm | 21 | Dry / high |
| May | 28.3°C | 30.3°C | 26.3°C | 255 mm | 26.9 | Green / low |
| June | 28.1°C | 29.7°C | 26.4°C | 235 mm | 23.1 | Green / low |
| July | 28°C | 29.5°C | 26.3°C | 206 mm | 22.8 | Green / low |
| August | 27.7°C | 29.2°C | 26°C | 254 mm | 25.7 | Green / low |
| September | 27.3°C | 28.9°C | 25.6°C | 325 mm | 25.1 | Green / low |
| October | 26.9°C | 28.8°C | 25.1°C | 336 mm | 27.1 | Green / low |
| November | 26.6°C | 28.9°C | 24.9°C | 245 mm | 25.4 | Green / low |
| December | 26.7°C | 29.5°C | 24.7°C | 126 mm | 15.9 | Dry / high |
Mean temperatures range from about 26.6°C in November to 28.6°C in March — Ko Lanta is warm all year. "Rainy days" counts days with at least 1mm of rain. Season labels are set from each month's rainfall against the annual average.
Common questions
FAQ- When is the best time to visit Koh Lanta?
- The best weather is in Ko Lanta's dry season, roughly December to April. February is the driest month of the year, averaging about 30mm of rain across only 6 rainy days, and the driest stretch overall is February, March and January. Daytime highs sit around 32°C with nights near 25°C, and the seas are calm enough that the fast ferries from Phuket and Phi Phi are running. This is high season, so it is also the busiest and priciest stretch.
- What is the rainy season on Koh Lanta?
- The southwest-monsoon (green) season runs roughly May to November, when most of the year's rain falls. It peaks in October, the wettest month, with about 336mm across 27 rainy days, with September close behind at about 325mm. The wettest months are October, September and May. Rain usually comes as heavy bursts rather than all-day drizzle, and it is warm throughout.
- How hot is Koh Lanta in March?
- March is the hottest month on Ko Lanta, averaging a daily high of about 32.3°C, an overnight low near 25.8°C, and a mean temperature of about 28.6°C. It is one of the drier months too, averaging about 55mm of rain.
- Is Koh Lanta worth visiting in the rainy season?
- Yes. Even in the wettest month, October, the mean temperature is about 26.9°C, so it stays warm. The rain tends to arrive in short heavy bursts with sunshine in between, the island is greener and far quieter, and prices are lower. The fast boats from Phuket and Phi Phi pause, but the year-round land route (minivan plus a short vehicle ferry) keeps Lanta reachable — see our ferry guide.
- How many rainy days does Koh Lanta get in October?
- October averages about 27 rainy days (days with at least 1mm of rain) and around 336mm of rain in total, making it the wettest month of the year. By contrast February, the driest month, averages only about 6 rainy days.
Climate normals computed from Open-Meteo / Copernicus ERA5 data, 2016-2025. Data licensed under CC-BY 4.0, via Open-Meteo.