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 Mai is June and the most expensive month to fly is November. (Average prices, based on 4486 datapoints.)
The best day to arrive at Bangkok is Tuesday and it would be best to avoid Saturday, as prices are on average 45.72% higher than on Tuesday. (Average prices, based on 8471 datapoints.)
The cheapest airline flying from Bangkok to Chiang Mai is Thai Vietjet Air. They are 41% cheaper than Bangkok Airways. (Average prices, based on 4528 datapoints.)
The best time to fly is at around 18. (Average prices, based on 10787 datapoints.)