Flight Chiang Mai International Airport departs from Chiang Mai Chiang Mai International Airport at 16:00 and arrives at Singapore Changi Airport at 19:55.
The flighttime is about 2h 55m. The distance travelled ("as the bird flies"): 673 Km. So the average speed is roughly 231 Km.
There is an 1 hour time difference between Chiang Mai and Singapore