Flight Changi Airport departs from Singapore Changi Airport at 01:35 and arrives at Seoul Incheon International Airport at 08:50.
The flighttime is about 6h 15m. The distance travelled ("as the bird flies"): 2923 Km. So the average speed is roughly 468 Km.
There is an 1 hour time difference between Singapore and Seoul
The best day to arrive at Singapore is Tuesday and it would be best to avoid Sunday, as prices are on average 61.21% higher than on Tuesday. (Average prices, based on 915818 datapoints.)
We have a lot more statistics for flights KE 646 and between Singapore and Seoul.