Chiang Mai Weather

Chiang Mai has a tropical climate, but is cooler and less humid than elsewhere in Thailand. Its southwest monsoon arrives from India at the end of May and lasts until November, with the heaviest downpours in September, which usually occur in the late afternoon. Between November and May, cool air blows in from China and northern Vietnam, bringing a dry season with mild days and balmy nights. Temperatures are at their lowest in December and January, chilly enough to require a warm jacket.

Cool season

During the cool season, temperatures reach a comfortable 25°C; nights and early morning are cool in the city at around 15°C, cold in the countryside at 10°C and possibly freezing in the mountains. The air turns crispy, and if you decide to ride a motorbike, take some protective clothing. Other than this, you will find that the sky is blue and cloudless.

Hot season

The hot season can be very hot, with an average April temperature of 36°C. Temperatures often go as high as 40°C during the hot season, and don’t usually drop below 25°C at night. The sun is scorching, making everyone feel lethargic between noon and 14:00.

Rainy season
Temperatures remain over 30°C during the rainy season, and evenings can be hot or cool, depending on whether it has rained or not. But, what you lose in temperature, you gain in humidity, meaning the weather can still be uncomfortable. Bad weather usually comes in three to four-day periods, and alternates with fine weather. Rain can come in any form at anytime of the day or night.

Average Temperature (°C)

30 22 15 8 0

Jan 21.2

Feb 23.4

Mar 26.2

Apr 28.8

May 28.7

Jun 27.9

Jul 27.4

Aug 27.1

Sep 27.0

Oct 26.3

Nov 24.3

Dec 21.6

Rainfall (mm)

260 195 130 65 0

Jan 7.5

Feb 6.0

Mar 15.0

Apr 44.9

May 153.1

Jun 135.8

Jul 167.1

Aug 227.0

Sep 251.3

Oct 132.0

Nov 43.9

Dec 14.8