Middle of the wetter season · Weather & things to do
Chiang Mai in September
Little changes in Chiang Mai from August: highs stay near 86°F (30°C), lows near 74°F (23°C), and about 8.7 in (222 mm) of rain falls.
With a comfort score of 33/100 (11th of 12), it's one of the toughest months, held back mainly by cloud cover.
- Avg high
- 86°F (30°C)
- Avg low
- 74°F (23°C)
- Rain
- 8.7 in (222 mm)
- Humidity
- 89%
- Cloud cover
- 89%
- Daylight
- ~12 h 06 min
- Comfort score
- 33/100 · Tough
What September feels like
Highs settle around 86°F (30°C), warm enough for short sleeves.
Nights stay warm too, with lows averaging 74°F (23°C).
With 89% average humidity, it feels muggy.
Rain is a real factor, with about 8.7 in (222 mm) across the month.
Skies are often grey, with average cloud cover around 89%.
Plan around September
September is one of the lower-scoring months here; the best are December & January.
- Inside the wettest three-month stretch, July – September.
- Comfort holds steady from August (31 → 33/100).
- Our Bangkok to the Andaman route recommends Nov – Mar, so September falls outside its suggested window.
What to pack for September
- Light, breathable clothes86°F afternoons
- Quick-dry fabrics89% average humidity
- Rain jacket and waterproof shoes8.7 in of rain on average
- Comfortable walking shoesmost picks involve some walking
What to do in Chiang Mai in September
Wet days call for a roof: these picks favor sit-down and indoor stops, plus a few for drier spells.
Khao Soi Khun Yai
Small lunch-only shop known for its khao soi curry noodle soup.
Why now A sit-down stop to wait out showers in a month with 8.7 in of rain.
Wat Chedi Luang
Partially ruined 14th-century chedi in the heart of the old city.
Warorot Market
Local market for dried foods, northern sausage and textiles near the river.
Elephant Nature Park
Sanctuary where you watch and feed rescued elephants without rides.
Chiang Mai Night Bazaar
Nightly market for crafts, clothing and food stalls.
Why now An indoor-leaning stop for a month with 8.7 in of rain.
NASA POWER 2001–2025 monthly averages on a ~50 km grid, temperatures adjusted from the grid cell's ~759 m to Chiang Mai's ~314 m elevation (standard lapse rate). Comfort scores weigh temperature, rain, humidity and cloud: see how we score each month. Check a forecast before you go.
Chiang Mai in September: quick answers
Is September a good time to visit Chiang Mai?
It's one of the tougher months here, scoring 33/100, held back mainly by cloud cover. The best months are December & January. Expect highs of 86°F (30°C) and 8.7 in (222 mm) of rain. Our Bangkok to the Andaman route recommends Nov – Mar, so September is outside its suggested window.
How hot is Chiang Mai in September?
Average highs are 86°F (30°C) and average lows 74°F (23°C), making it the 5th-coldest month by daytime highs.
Does it rain a lot in Chiang Mai in September?
Yes: about 8.7 in (222 mm) of rain falls across September on average, the 2nd-wettest month of the year. The annual total is about 49.1 in (1246 mm).
What should I pack for Chiang Mai in September?
Bring light, breathable clothes (86°F afternoons), quick-dry fabrics (89% average humidity), rain jacket and waterproof shoes (8.7 in of rain on average) and comfortable walking shoes (most picks involve some walking).
More on Chiang Mai
Planning Chiang Mai in September?
Bring the crew into one shared trip: vote on dates, build the day-by-day plan, split costs and share one packing list.