Climate and Weather in Chiang Mai
Current Weather Map of Chiang Mai
You can click on the weather icons to get more detailed information.
Chiang Mai Weather Patterns
Chiang Mai and Northern Thailand's climate is characterized by the monsoon which creates three distinct seasons.
The south-west monsoon usually arrives from India at the end of May and lasts until November. Rainfall is generally heaviest in September with an average precipitation of 250 mm for that month alone. Rainy season however does not mean drizzle for days on end. The normal pattern over the last years has been: clear mornings (with better-than-dry-season visibility and mountain views), clouds in the afternoon and subsequent rain, dry evenings, occasional rain at night. Still, weather is ruled by chaos principles so there can be clouds and rainy days for -mostly short- continuous periods.
The north-east monsoon lasts from mid-November until early May and brings cool air from northern Vietnam/China but no rain for Northern and Central Thailand except for the occasional "mango showers" which may occur during the mango season.
This provides for a dry season of about six months every year while Phuket and Southern Thailand barely get 2 months.
From March to May heat is on the agenda and maximum daytime temperatures reach 40°C/100°F. Still, at night it mostly cools down substantially and mornings can be quite pleasant, evenings balmy.
Year round the air is less humid than in other parts of the country. The low humidity is the main reason why the air seems more pleasant here. Moreover, the temperature difference between day and night and between the seasons is greater than in the other regions.
If you plan to visit during the cold season, especially around Christmas and New Year when it gets coldest, be sure to bring warm clothes which means a pullover anda jacket. In Chiang Rai and Mae Hong Son it will be even chillier. Going on a mountain trek during this time can be a very freezing business so bring an adequate down sleeping bag from home, since you'll hardly find a good one in Thailand.
At a glance:
- Chiang Mai's climate is tropical but cooler and less humid than elsewhere in Thailand (the temperate zone begins only 300 kms/200 miles north of Chiang Mai).
- It's more continental than Southern Thailand with distinct and shorter monsoon seasons.
- It can get downright cold in December/January.
- All seasons make for a great stay!