Flight Don Mueang International Airport departs from Bangkok Don Mueang International Airport at 14:25 and arrives at Surat Thani Surat Thani International Airport at 15:35.
The flighttime is about 1h 10m. The distance travelled ("as the bird flies"): 187 Km. So the average speed is roughly 160 Km.
The best day to arrive at Bangkok is Friday and it would be best to avoid Sunday, as prices are on average 17.9% higher than on Friday. (Average prices, based on 783076 datapoints.)
We have a lot more statistics for flights SL 740 and between Bangkok and Surat Thani.