Flight Changi Airport departs from Singapore Changi Airport at 16:15 and arrives at Hong Kong Hong Kong International Airport at 20:20.
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 Sunday, as prices are on average 47.41% higher than on Tuesday. (Average prices, based on 2250347 datapoints.)
This graph shows the distribution of prices found in the past years for this flight. (Average prices, based on 136 datapoints.)
We have a lot more statistics for flights TR 980 and between Singapore and Hong Kong.