Flight Changi Airport departs from Singapore Changi Airport at 18:00 and arrives at Koh Samui Samui International Airport at 18:50.
The flighttime is about 1h 50m. The distance travelled ("as the bird flies"): 475 Km. So the average speed is roughly 259 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 144.63% higher than on Thursday. (Average prices, based on 93897 datapoints.)
We have a lot more statistics for flights TR 648 and between Singapore and Koh Samui.