When to go · Chiang Mai
Chiang Mai in September
Avoid month. Outside the best window (Nov–Jan (cooler and dry)). Across Thailand: Wettest month in Bangkok and on the Andaman coast; flooding in low areas. Only for low prices.
Key facts
- Verdict
- Avoid
- Temperature
- 31°C (88°F)88°F (31°C) / 24°C (75°F)75°F (24°C)
- average high / low
- Rain days
- 19
- Crowds
- Low
- Thailand overall
- Prices
- Low
- Thailand overall
Verdict
Outside the best window (Nov–Jan (cooler and dry)). Across Thailand: Wettest month in Bangkok and on the Andaman coast; flooding in low areas. Only for low prices.
Is another month better than September?
September is rated avoid. These months rate higher:
- NovemberGreatInside Chiang Mai's best window: Nov–Jan (cooler and dry).
- DecemberGreatInside Chiang Mai's best window: Nov–Jan (cooler and dry).
- JanuaryGreatInside Chiang Mai's best window: Nov–Jan (cooler and dry).
- OctoberMixedOutside the best window (Nov–Jan (cooler and dry)). Across Thailand: Rain eases in Bangkok and the north late in the month; the Gulf islands start their wet season.
Weather in September
- Chiang MaiHighs around 31 °C (88 °F), lows around 24 °C (75 °F), rain on about 19 daysHighs around 88 °F (31 °C), lows around 75 °F (24 °C), rain on about 19 days
- North, Thailand · Chiang Mai, Chiang Rai, Pairainy
Cool nights Dec–Jan; the burning season (Feb–Apr) puts air quality among the worst in Asia — check AQI before booking.
Crowds and prices
- Crowds · Thailand overall
- Low
- Prices · Thailand overall
- Low
Thailand overall: Wettest month in Bangkok and on the Andaman coast; flooding in low areas. Only for low prices.
Compare two months
Weather, crowds and prices for any two months in Chiang Mai, side by side.
Verdict
Sep: Avoid
Jan: Great (better)
Daytime high
Sep: 31 °C (88 °F)88 °F (31 °C)
Jan: 30 °C (86 °F)86 °F (30 °C)
Night low
Sep: 24 °C (75 °F)75 °F (24 °C)
Jan: 15 °C (59 °F)59 °F (15 °C)
Rain days
Sep: 19
Jan: 2 (better)
Crowds
Sep: Low
Jan: High
Prices
Sep: Low
Jan: High
Festivals listed
Sep: 0
Jan: 0
September: Outside the best window (Nov–Jan (cooler and dry)). Across Thailand: Wettest month in Bangkok and on the Andaman coast; flooding in low areas. Only for low prices.
January: Inside Chiang Mai's best window: Nov–Jan (cooler and dry).
Chiang Mai: figures are long-term averages from this guide, not a forecast.
What to pack
- Light, breathable clothes, a sun hat and sunscreen
- A rain jacket or umbrella and shoes that dry fast