Flight Guangzhou Baiyun International Airport departs from Guangzhou Guangzhou Baiyun International Airport at 13:25 and arrives at Singapore Changi Airport at 17:45.
The flighttime is about 4h 20m. The distance travelled ("as the bird flies"): 1282 Km. So the average speed is roughly 296 Km.
The best day to arrive at Guangzhou is Saturday and it would be best to avoid Wednesday, as prices are on average 255.52% higher than on Saturday. (Average prices, based on 122326 datapoints.)
We have a lot more statistics for flights SQ 851 and between Guangzhou and Singapore.