Flight Indira Gandhi International Airport departs from Delhi Indira Gandhi International Airport at 08:55 and arrives at Dehradun Dehradun Airport at 09:40.
The flighttime is about 0h 45m. The distance travelled ("as the bird flies"): 125 Km. So the average speed is roughly 167 Km.
The best day to arrive at Delhi is Wednesday and it would be best to avoid Sunday, as prices are on average 150.59% higher than on Wednesday. (Average prices, based on 86525 datapoints.)
We have a lot more statistics for flights 6E 2018 and between Delhi and Dehradun.