September · Thailand
Best time to visit Koh Tao in September Weather, crowds & prices
Weather in Koh Tao in September
Average temperature 29°C, 265 mm of rain, about 17 days with 6+ hours of sunshine and 80% humidity — based on the five most recent complete years of ERA5 data (2021–2025).
September score
6.0/10
Ranked #8 of 12 months
- Avg temp
- 29°C
- Rainfall
- 265 mm
- Humidity
- 80%
- Days with 6h+ sun
- 17
- Crowd Density
- Quiet / Uncrowded
- Average Expenses
- $ · Budget Friendly ($)
September in Koh Tao scores 6.0/10 for beach and coastal travel - ranked #8 of 12. Expect around 29°C, 265 mm of rain, and roughly 17 days with 6+ hours of sunshine this month.
Ko Tao is Thailand's dive-cert island-compact coves, training reefs, and a backpacker nightlife pocket in Mae Haad. Best window: the drier months outside peak monsoon.
September in Koh Tao — middling scores, decent value
Days in September average 29°C (83°F) and humidity near 80% — front-load outdoor plans before the heat builds and treat the middle of the day as indoor time.
Expect monsoon-level rainfall at 265 mm: only about 17 days with 6+ hours of sunshine across the month, and stretches of heavy rain are normal.
That is 6/10 on the same scale — 8th of 12 months, versus 9.2/10 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, March is materially better in Koh Tao — 3.2 points higher on the same scale.
Frequently asked
- What is the weather like in Koh Tao in September?
- In September, Koh Tao averages 29°C, 265 mm of rain, and about 17 days with 6+ hours of sunshine. Its climate-comfort score is 6.0/10.
- Is September a good time to visit Koh Tao?
- September earns a 6.0/10 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 Tao in September?
- Expect about 265 mm of rain in September. Average humidity is 80% and there are about 17 days with 6+ hours of sunshine.
Curated in Koh Tao
Tickets & experiences
Things to do in Koh Tao
Koh Tao, Thailand. Live activities and tours from GetYourGuide, matched to this destination.