Flight Changi Airport departs from Singapore Changi Airport at 18:00 and arrives at Hong Kong Hong Kong International Airport at 22:05.
The flighttime is about 4h 05m. The distance travelled ("as the bird flies"): 1322 Km. So the average speed is roughly 324 Km.
The best day to arrive at Singapore is Tuesday and it would be best to avoid Friday, as prices are on average 51.82% higher than on Tuesday. (Average prices, based on 4110507 datapoints.)
We have a lot more statistics for flights CX 716 and between Singapore and Hong Kong.
