Flight Changi Airport departs from Singapore Changi Airport at 10:00 and arrives at Koh Samui Samui International Airport at 11:00.
The flighttime is about 2h 00m. The distance travelled ("as the bird flies"): 475 Km. So the average speed is roughly 238 Km.
There is an 1 hour time difference between Singapore and Koh Samui
The best day to arrive at Singapore is Thursday and it would be best to avoid Monday, as prices are on average 139.35% higher than on Thursday. (Average prices, based on 93953 datapoints.)
We have a lot more statistics for flights TR 642 and between Singapore and Koh Samui.