The best month to fly between Surat Thani and Bangkok is November and the most expensive month to fly is August. (Average prices, based on 1025 datapoints.)
The best day to arrive at Surat Thani is Tuesday and it would be best to avoid Sunday, as prices are on average 102.6% higher than on Tuesday. (Average prices, based on 1111 datapoints.)
The best time to fly is at around 11. (Average prices, based on 1106 datapoints.)