Flight Changi Airport departs from Singapore Changi Airport at 13:25 and arrives at Shenzhen Shenzhen Bao'an International Airport at 17:50.
The flighttime is about 4h 25m. The distance travelled ("as the bird flies"): 1318 Km. So the average speed is roughly 298 Km.
The best day to arrive at Singapore is Wednesday and it would be best to avoid Thursday, as prices are on average 281.62% higher than on Wednesday. (Average prices, based on 133825 datapoints.)
We have a lot more statistics for flights CZ 8118 and between Singapore and Shenzhen.
