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 August and the most expensive month to fly is October. (Average prices, based on 2806 datapoints.)
The best day to arrive at Bangkok is Wednesday and it would be best to avoid Monday, as prices are on average 44.96% higher than on Wednesday. (Average prices, based on 2832 datapoints.)
The cheapest airline flying from Bangkok to Singapore is Thai Lion Air. They are 64% cheaper than Singapore Airlines. (Average prices, based on 2827 datapoints.)
The best time to fly is at around 7. (Average prices, based on 5493 datapoints.)