Chiang Mai weather in September 2026
Expect daytime maximum temperatures of 30°C in Chiang Mai, Thailand in September and high heat and humidity based on long-term weather averages. There are 6 hours of sunshine per day on average with 18 days with some rainfall and typically 224 mm of rainfall in the month.
- 30°C max day temperature
30 - 6 hours of sunshine per day
- 18 days with some rainfall
18 - 22°C min night temperature
22 - 12 hours of daylight per day
12 - High heat & humidity
H - 224 mm of monthly rainfall
224 - 11+ (Extreme) UV index
11
