Please be aware that Bangkok has multiple airports and that these results are for all airports serving the city.
The best month to fly between Bangkok and Chiang Rai is June and the most expensive month to fly is November. (Average prices, based on 1283 datapoints.)
The best day to arrive at Bangkok is Wednesday and it would be best to avoid Friday, as prices are on average 61.49% higher than on Wednesday. (Average prices, based on 915 datapoints.)
The cheapest airline flying from Bangkok to Chiang Rai is Thai Vietjet Air. They are 11% cheaper than Thai AirAsia. (Average prices, based on 1294 datapoints.)
The best time to fly is at around 18. (Average prices, based on 2202 datapoints.)