Chiang Mai Weather is very consistent and mainly features three seasons: the cool season, the hot season and the rainy season.
Chiang Mai Weather Forecast for Today, by Month & Year in Thailand
The worst time to visit Chiang Mai is during March and April which is when the ‘burning season’ starts. Temperatures start to climb to around 35 degrees during the day and the farmers start burning their crops. This leads to a murky haze hanging over the city and if you suffer from hayfever, you will certainly notice the difference in your allergies. Because of the pollution in the air, you will find that many of the beautiful views form the mountains will be obscured by haze during this time.
May and June remain hot during the days and nights and the monsoon season typically arrives around June and runs through to November. The days remain hot at over 30 degrees each day, however there may be torrential downpours every few days. You wont find solidly rainy days in Chiang Mai, but rather a burst of heavy rain that will last for an hour or two and then pass. During these times it is not uncommon for roads to flood, so be mindful when making travel plans. Note that rainfall in Chiang Mai is usually heaviest in the month of September.
Chiang Mai is a great place to holiday in part due to its consistent weather. Predictable weather means that you only need to pack shorts and t-shirts as Chiang Mai Weather is mostly hot and sunny. The air is not humid like Bangkok which means that once you are out of the sun, the air temperature is quite pleasant.