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 585 datapoints.)
The best day to arrive at Bangkok is Wednesday and it would be best to avoid Friday, as prices are on average 66.25% higher than on Wednesday. (Average prices, based on 585 datapoints.)
The cheapest airline flying from Bangkok to Chiang Rai is Thai Lion Air. They are 34% cheaper than Thai Airways. (Average prices, based on 602 datapoints.)
The best time to fly is at around 16. (Average prices, based on 1576 datapoints.)