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 Yangon is August and the most expensive month to fly is May. (Average prices, based on 205 datapoints.)
The best day to arrive at Bangkok is Monday and it would be best to avoid Tuesday, as prices are on average 56.5% higher than on Monday. (Average prices, based on 255 datapoints.)
The cheapest airline flying from Bangkok to Yangon is Thai AirAsia. They are 73% cheaper than Myanmar Airways. (Average prices, based on 212 datapoints.)