Flight Suvarnabhumi Airport departs from Bangkok Suvarnabhumi Airport at 17:05 and arrives at Phuket Phuket International Airport at 18:30.
The flighttime is about 1h 25m. The distance travelled ("as the bird flies"): 290 Km. So the average speed is roughly 205 Km.
The best month to arrive at Bangkok is June and the most expensive month to fly is December. (Average prices, based on 252 datapoints.)
We have a lot more statistics for flights GA 277 and between Bangkok and Phuket.