Chiang Mai Weather in September

Chiang Mai in September sees very high daytime temperatures of 33°C (91°F) and nighttime lows of 24°C (75°F). As part of the rainy season, showers are frequent and often heavy. Budget around 249 mm (9.8 in) of rainfall for the month.

Rainfall in Chiang Mai in September

As part of the rainy season, Chiang Mai sees around 18 days of rain in September, with an average of 249 mm (9.8 in). With rain on many days and solid totals, showers are frequent and often moderately heavy. Waterproof gear is a sensible idea.

Temperature in Chiang Mai in September

Daytime highs in Chiang Mai in September reach 33°C (91°F), with nights around 24°C (75°F). Sunshine and humidity can make it feel even warmer than the raw temperature suggests. With lows around 24°C (75°F), the nights are warm enough that a sheet is usually all you need for bedding.

Sunshine in Chiang Mai in September

The month experiences a moderate amount of sunlight, with 148 hours of sunshine. This provides a nice balance between sunshine and rain.

Wind Speed in Chiang Mai in September

Wind speeds average 1 m/s (2 knots) during September. At this speed, you'll experience mostly light air movement that's just barely noticeable. As an average, some days will be completely calm while others have gentle breezes you can feel on your skin.

If you're looking for dry conditions and comfortable temperatures, September may not be the ideal month to visit Chiang Mai. Our weather planner can help you explore destinations with more pleasant weather conditions.

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For a detailed overview over the year and the best time to visit Thailand, check out our Chiang Mai's climate page.

Chiang Mai Temperature in September

Min Temperature 24°C (75°F)  

Max Temperature 33°C (91°F)  

Chance of Rain 60%  

Precipitation 249 mm (9.8 in)  

Rainy days 18 days  

Humidity 81%  

Windspeed 1 m/s (2 knots)  

Sunshine 148 hours  

Percentage Sunshine  

Daily Historical Temperatures

50-year average (1976-2025)

Based on our historical records, temperatures in Chiang Mai typically stay consistent throughout September, with daily highs averaging around 33°C (91°F). Nights are warm, with lows around 24°C (75°F).

Average temperatures in September

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Daily Historical Precipitation

50-year average (1976-2025)

Average daily rainfall for each day of the month based on long-term records.

Average precipitation in September

‹ Select year to compare to 2026 2025 2024 2023 2022 2021 2020 2019 2018 2017 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 1989 1988 1987 1986 1985 1984 1983 1982 1981 1980 1979 1978 1977 1976 ›

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

‹ January February March April May June July August September October November December ›

Historical weather for Chiang Mai in September

Browse day-by-day weather records for Chiang Mai spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.

Historical weather Temperatures Precipitation

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‹ January February March April May June July August September October November December ›

Chiang Mai historical weather extremes in September

Based on weather observations in Chiang Mai between 1976 and 2025, these are the recorded extremes during September.

• The warmest day in September was on September 10, 1979, with a maximum of 38°C (100°F).
• On September 12, 1999, Chiang Mai saw its coldest September day with temperatures maxing out at 24°C (75°F).
• Nighttime temperatures dropped to 17°C (63°F) on September 25, 1977, marking the coldest September night on record.

What to Wear in Chiang Mai in September

Warm weather calls for comfortable, breathable clothing in September. Cotton t-shirts, shorts, light dresses, and sandals are perfect. You might still want a light layer for evenings or air-conditioned places (for example buses). Also bring a poncho, it will rain a lot! Waterproof everything you can. It won't hurt to bring your sunglasses along, as you'll see some sunny periods.

What To Do in Chiang Mai in September

We rated the following activities from 1 (least suitable) to 10 (best) to do.

Swimming

7/10

Cycling

7/10

Walking

7/10

Camping

6/10

Outdoor sports

7/10

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit Thailand, check out our Chiang Mai's climate page.

More climate data for Chiang Mai

Temperature Rainfall Sunshine Humidity Wind Speed

See the full Chiang Mai climate overview or explore weather in Thailand.