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 Singapore is May and the most expensive month to fly is December. (Average prices, based on 17458 datapoints.)
The best day to arrive at Bangkok is Wednesday and it would be best to avoid Sunday, as prices are on average 38.17% higher than on Wednesday. (Average prices, based on 17104 datapoints.)
The cheapest airline flying from Bangkok to Singapore is Thai AirAsia. They are 52% cheaper than Thai Airways. (Average prices, based on 17473 datapoints.)