The best time to visit Chiang Rai begins with the end of the monsoons from November to mid-February, when the burning of the fields causes the atmosphere to begin to be less clean and the forests a little drier due to the lack of rain, until May.
Nevertheless, the interest of the Golden Triangle and the Hill Tribes remain, since in those months it is precisely when the entry of the new year is celebrated in many of their communities (from February to April). An opportunity to participate in a unique moment that is worth sharing.
In the monsoons (from May to October) keep in mind that the probability of rain increases, pay attention to the weather forecast and be careful with the dirt roads. Nature will be gorgeous, the forest with intense greens and the streams full of water.
The rice fields will have a lot of life since this is their season.
Chiang Rai has an airport with good air links to Bangkok, from where you can also travel at night by bus, preferably by S-VIP bus (24 seats) for an 11 hours trip or so.
It also has a good connection with Chiang Mai, buses depart from 06h00 to 17h30, on a journey of 200 km that lasts approximately 3 hours.