September · Thailand
Best time to visit Chiang Mai in September Weather, crowds & prices
Weather in Chiang Mai in September
Average temperature 24°C, 366 mm of rain, about 14 days with 6+ hours of sunshine and 90% humidity — based on the five most recent complete years of ERA5 data (2021–2025).
September score
4.0/10
Ranked #12 of 12 months
- Avg temp
- 24°C
- Rainfall
- 366 mm
- Humidity
- 90%
- Days with 6h+ sun
- 14
- Crowd Density
- Quiet / Uncrowded
- Average Expenses
- $ · Budget Friendly ($)
September in Chiang Mai scores 4.0/10 for sightseeing and cultural travel - ranked #12 of 12. Expect around 24°C, 366 mm of rain, and roughly 14 days with 6+ hours of sunshine this month.
Temple mountains, night markets, and cooler northern air shine January through March.
September in Chiang Mai — the hardest end of the year
September averages 24°C (75°F) — pleasant for mornings and evenings on foot in the city, with a midday break when the sun is strongest.
366 mm of rain puts this in monsoon territory — about 14 days with 6+ hours of sunshine across the whole month, and multi-day washouts are normal.
It scores 4/10 here, 12th of 12 months, against 9.8/10 in the destination's best month.
Pack light clothing, a hat and real sun protection, a proper rain shell rather than an umbrella.
Figure on low-season pricing, with crowds are light for this destination.
Flexible dates? February scores 5.8 points higher here — enough to change the trip.
Frequently asked
- What is the weather like in Chiang Mai in September?
- In September, Chiang Mai averages 24°C, 366 mm of rain, and about 14 days with 6+ hours of sunshine. Its climate-comfort score is 4.0/10.
- Is September a good time to visit Chiang Mai?
- September earns a 4.0/10 climate-comfort score. Use the year-round chart to weigh the weather against your budget and crowd preferences.
- How much does it rain in Chiang Mai in September?
- Expect about 366 mm of rain in September. Average humidity is 90% and there are about 14 days with 6+ hours of sunshine.
Curated in Chiang Mai
Tickets & experiences
Things to do in Chiang Mai
Chiang Mai, Thailand. Live activities and tours from GetYourGuide, matched to this destination.