Flight Don Mueang International Airport departs from Bangkok Don Mueang International Airport at 21:20 and arrives at Chiang Mai Chiang Mai International Airport at 22:30.
The flighttime is about 1h 10m. The distance travelled ("as the bird flies"): 204 Km. So the average speed is roughly 175 Km.
The best day to arrive at Bangkok is Tuesday and it would be best to avoid Friday, as prices are on average 79.32% higher than on Tuesday. (Average prices, based on 19212661 datapoints.)
We have a lot more statistics for flights DD 142 and between Bangkok and Chiang Mai.