Flight Samui International Airport departs from Koh Samui Samui International Airport at 21:30 and arrives at Bangkok Suvarnabhumi Airport at 23:00.
The flighttime is about 1h 30m. The distance travelled ("as the bird flies"): 113 Km. So the average speed is roughly 75 Km.
The best day to arrive at Koh Samui is Friday and it would be best to avoid Wednesday, as prices are on average 124.7% higher than on Friday. (Average prices, based on 1300724 datapoints.)
We have a lot more statistics for flights PG 196 and between Koh Samui and Bangkok.
