Flight Changi Airport departs from Singapore Changi Airport at 05:15 and arrives at Guangzhou Guangzhou Baiyun International Airport at 09:25.
The flighttime is about 4h 10m. The distance travelled ("as the bird flies"): 1282 Km. So the average speed is roughly 308 Km.
The best day to arrive at Singapore is Thursday and it would be best to avoid Saturday, as prices are on average 2280.57% higher than on Thursday. (Average prices, based on 450859 datapoints.)
We have a lot more statistics for flights SQ 8430 and between Singapore and Guangzhou.
