Flight Incheon International Airport departs from Seoul Incheon International Airport at 14:45 and arrives at Singapore Changi Airport at 19:55.
The flighttime is about 6h 10m. The distance travelled ("as the bird flies"): 2923 Km. So the average speed is roughly 474 Km.
There is an 1 hour time difference between Seoul and Singapore
The best day to arrive at Seoul is Wednesday and it would be best to avoid Sunday, as prices are on average 96.52% higher than on Wednesday. (Average prices, based on 265410 datapoints.)
We have a lot more statistics for flights KE 643 and between Seoul and Singapore.
THB
