What to pack for Chiang Mai in September
- light, breathable clothing
- sun protection (hat, SPF 50)
- a compact umbrella or rain shell — rain is frequent
- expect humid, sticky conditions
Humidity averages 86%; max daily wind around 8 km/h.
How September compares
Best months in Chiang Mai: December–January. See the full best time to visit Chiang Mai guide.
Chiang Mai in September: the details
In September, Chiang Mai sees average daytime highs of 30°C (85°F) and overnight lows of 23°C (74°F). Rainfall totals roughly 393 mm across 26 rainy days, and the sun shines about 8.8 hours per day with 12.1 hours of daylight mid-month. Relative humidity averages 86%.
In context: September is the 7th-warmest month and the second-wettest in Chiang Mai. The sunniest month is April (10.9 h/day).
| Metric | September average |
|---|---|
| Daytime high | 30°C / 85°F |
| Overnight low | 23°C / 74°F |
| Rainfall | 393 mm over 26 rainy days |
| Sunshine | 8.8 h/day (12.1 h daylight) |
| Humidity | 86% |
| Travel score | 4.4 / 10 |
These figures are climate normals computed from the ERA5 weather reanalysis (2019–2024) for Chiang Mai, Thailand (18.79, 98.98) — see our methodology. Actual conditions vary year to year.
Not set on Chiang Mai? Browse the best places to visit in September ranked by travel score.
Frequently asked questions
How hot is Chiang Mai in September?
Daytime highs in Chiang Mai in September average 30°C (85°F); nights drop to about 23°C.
Does it rain in Chiang Mai in September?
Expect around 26 rainy days and 393 mm of rainfall in September.
Is September a good time to visit Chiang Mai?
September is a challenging month to visit Chiang Mai — consider December–January instead. Overall travel score: 4.4/10. The best months are December–January.
Also good in September, near Chiang Mai
Where should you go next month?
Get one email a month with the destinations at their seasonal best. Double opt-in, unsubscribe anytime.