Flight Don Mueang International Airport departs from Bangkok Don Mueang International Airport at 21:55 and arrives at Chiang Mai Chiang Mai International Airport at 23:10.
The flighttime is about 1h 15m. The distance travelled ("as the bird flies"): 204 Km. So the average speed is roughly 163 Km.
The best day to arrive at Bangkok is Saturday and it would be best to avoid Sunday, as prices are on average 24.3% higher than on Saturday. (Average prices, based on 14756040 datapoints.)
We have a lot more statistics for flights JT 518 and between Bangkok and Chiang Mai.