September · Thailand
Best time to visit Koh Lanta in September Weather, crowds & prices
Weather in Koh Lanta in September
Average temperature 27°C, 394 mm of rain, about 16 days with 6+ hours of sunshine and 87% humidity — based on the five most recent complete years of ERA5 data (2021–2025).
September score
5.6/10
Ranked #11 of 12 months
- Avg temp
- 27°C
- Rainfall
- 394 mm
- Humidity
- 87%
- Days with 6h+ sun
- 16
- Crowd Density
- Quiet / Uncrowded
- Average Expenses
- $ · Budget Friendly ($)
September in Koh Lanta scores 5.6/10 for beach and coastal travel - ranked #11 of 12. Expect around 27°C, 394 mm of rain, and roughly 16 days with 6+ hours of sunshine this month.
Koh Lanta's quiet beaches and long sunsets suit families and travellers avoiding the crowds.
September in Koh Lanta — workable with trade-offs
Days in September average 27°C (80°F) and humidity near 87% — front-load outdoor plans before the heat builds and treat the middle of the day as indoor time.
Expect monsoon-level rainfall at 394 mm: only about 16 days with 6+ hours of sunshine across the month, and stretches of heavy rain are normal.
That is 5.6/10 on the same scale — 11th of 12 months, versus 8.7/10 for the best month here.
Pack the lightest breathable clothing you own, a hat, and more water than feels necessary, a proper rain shell rather than an umbrella.
Budget for low-season pricing, and crowds are light for this destination.
If your dates are flexible, February is materially better in Koh Lanta — 3.1 points higher on the same scale.
Frequently asked
- What is the weather like in Koh Lanta in September?
- In September, Koh Lanta averages 27°C, 394 mm of rain, and about 16 days with 6+ hours of sunshine. Its climate-comfort score is 5.6/10.
- Is September a good time to visit Koh Lanta?
- September earns a 5.6/10 climate-comfort score. Use the year-round chart to weigh the weather against your budget and crowd preferences.
- How much does it rain in Koh Lanta in September?
- Expect about 394 mm of rain in September. Average humidity is 87% and there are about 16 days with 6+ hours of sunshine.
Curated in Koh Lanta
Tickets & experiences
Things to do in Koh Lanta
Koh Lanta, Thailand. Live activities and tours from GetYourGuide, matched to this destination.