Flight Incheon International Airport departs from Seoul Incheon International Airport at 12:35 and arrives at Singapore Changi Airport at 18:20.
The flighttime is about 6h 45m. The distance travelled ("as the bird flies"): 2923 Km. So the average speed is roughly 433 Km.
There is an 1 hour time difference between Seoul and Singapore
The best day to arrive at Seoul is Saturday and it would be best to avoid Thursday, as prices are on average 149.83% higher than on Saturday. (Average prices, based on 690595 datapoints.)
We have a lot more statistics for flights VA 5681 and between Seoul and Singapore.
