Flight Suvarnabhumi Airport departs from Bangkok Suvarnabhumi Airport at 11:00 and arrives at Hat Yai Hat Yai International Airport at 12:30.
The flighttime is about 1h 30m. The distance travelled ("as the bird flies"): 143 Km. So the average speed is roughly 95 Km.
The best day to arrive at Bangkok is Saturday and it would be best to avoid Wednesday, as prices are on average 63% higher than on Saturday. (Average prices, based on 314654 datapoints.)
We have a lot more statistics for flights VZ 324 and between Bangkok and Hat Yai.