Thailand Chiang Mai Weather in September — Climate Guide
September in Chiang Mai is moderate
September is moderate for Chiang Mai.
Tail end of rainy season — countryside at peak green lush. Hotels lowest of year. Off-peak ideal for budget travelers.
Travel score
Chiang Mai September Weather Stats
Avg High
32°C
Avg Low
23°C
Rainy Days
17
200mm total
Sunshine
6h
Daily avg
Humidity
82%
high
UV Index
8
Very high
Wind
6 km/h
Gusts 15
Sea Temp
0°C
no swimming
Crowds
Quiet
At attractions
September Sunrise & Sunset
Air Quality
PM2.5
18 μg/m³
PM10
30 μg/m³
Status
good
Feels-Like Temperature & Wind
Feels like
Daytime
35°C
Nighttime
24°C
Humidity and wind affect how the actual temperature feels.
Wind
6 km/h
Max gust 15 km/h
Activities Recommended for September
September Travel Pros & Cons
Pros
- Hotels lowest of year
- Lush countryside peak
- Crowd-free
Cons
- 200mm rain
- Daily storms
- Humid 82%
September Events & Festivals
- End of rainy season
Chiang Mai in September — Full Picture
Tail end of rainy season — countryside at peak green lush. Hotels lowest of year. Off-peak ideal for budget travelers.
What to Wear & What to Pack
Still wet. T-shirt + raincoat + waterproof shoes.
Packing Checklist
Seasonal Weather Overview
Spring (Mar·Apr·May)
34.7°C
22°C
6.3/mo
Summer (Jun·Jul·Aug)
32°C
23°C
14.3/mo
Autumn (Sep·Oct·Nov)
Current30.3°C
21°C
11.3/mo
Winter (Dec·Jan·Feb)
29°C
15.7°C
2/mo
Chiang Mai Monthly Weather Comparison
| Month | High | Low | Rain | Sun | Humid | UV | Crowd | Price |
|---|---|---|---|---|---|---|---|---|
| January (Best) | 28° | 15° | 2d·10mm | 8h | 65% | 7 | Very busy | Peak |
| February (Best) | 31° | 17° | 2d·10mm | 9h | 60% | 8 | Very busy | Peak |
| 34° | 20° | 3d·25mm | 9h | 60% | 10 | Busy | Shoulder | |
| 36° | 23° | 5d·50mm | 8h | 65% | 11 | Busy | Peak | |
| 34° | 23° | 11d·150mm | 7h | 75% | 11 | Quiet | Low season | |
| 32° | 23° | 13d·130mm | 6h | 80% | 10 | Quiet | Low season | |
| 32° | 23° | 14d·150mm | 6h | 80% | 10 | Moderate | Shoulder | |
| 32° | 23° | 16d·175mm | 6h | 82% | 9 | Moderate | Shoulder | |
| 32° | 23° | 17d·200mm | 6h | 82% | 8 | Quiet | Low season | |
| 30° | 22° | 12d·130mm | 7h | 80% | 8 | Moderate | Shoulder | |
| November (Best) | 29° | 18° | 5d·50mm | 8h | 70% | 7 | Very busy | Peak |
| December (Best) | 28° | 15° | 2d·15mm | 8h | 65% | 7 | Very busy | Peak |
View Other Months
Chiang Mai September Hotel Picks
Frequently Asked Questions
Is September a good time to visit Chiang Mai?
Chiang Mai in September is moderate. Tourist crowds are quiet and flight/hotel prices are low season.
What's the average temperature in Chiang Mai in September?
Chiang Mai September averages a high of 32°C and a low of 23°C.
Does it rain much in Chiang Mai in September?
Chiang Mai September averages 200mm of rainfall over about 17 rainy days.
What should I wear in Chiang Mai in September?
Still wet. T-shirt + raincoat + waterproof shoes.
What time are sunrise and sunset in Chiang Mai in September?
Chiang Mai September sunrise is 06:00 and sunset is 18:15, with 12h 15min of daylight.
What's the air quality like in Chiang Mai in September?
Chiang Mai September air quality (AQI) averages 50, rated Good. PM2.5 averages 18μg/m³.
What activities are recommended in Chiang Mai in September?
In September, Chiang Mai is great for Morning Old City, Indoor afternoon, Spa retreats.
Is September peak season in Chiang Mai?
Chiang Mai September crowds are quiet and prices are low season. You can travel relatively comfortably without long queues.
Best Months to Visit Chiang Mai
View Other Months
Why you can trust weather guide
Based in Chiang Mai for 8+ years, with 30+ countries visited across Southeast Asia, Japan, and Europe. Every detail in this guide is primary-source verified as of April 2026, with prices auto-refreshed via live exchange rate APIs. This isn't AI-generated boilerplate — it's written from the perspective of someone who has actually been there.