Flight Incheon International Airport departs from Seoul Incheon International Airport at 16:15 and arrives at Hong Kong Hong Kong International Airport at 19:00.
The flighttime is about 3h 45m. The distance travelled ("as the bird flies"): 1621 Km. So the average speed is roughly 432 Km.
There is an 1 hour time difference between Seoul and Hong Kong
The best day to arrive at Seoul is Thursday and it would be best to avoid Friday, as prices are on average 160.85% higher than on Thursday. (Average prices, based on 18504379 datapoints.)
We have a lot more statistics for flights UO 631 and between Seoul and Hong Kong.