Flight Samui International Airport departs from Koh Samui Samui International Airport at 20:30 and arrives at Bangkok Suvarnabhumi Airport at 21:45.
The flighttime is about 1h 15m. The distance travelled ("as the bird flies"): 113 Km. So the average speed is roughly 90 Km.
The best day to arrive at Koh Samui is Sunday and it would be best to avoid Tuesday, as prices are on average 101.37% higher than on Sunday. (Average prices, based on 1360251 datapoints.)
We have a lot more statistics for flights PG 178 and between Koh Samui and Bangkok.
