Flight Kualanamu International Airport departs from Medan Kualanamu International Airport at 21:00 and arrives at Jakarta Soekarno–Hatta International Airport at 23:25.
The flighttime is about 2h 25m. The distance travelled ("as the bird flies"): 895 Km. So the average speed is roughly 370 Km.
The best month to arrive at Medan is March and the most expensive month to fly is January. (Average prices, based on 3976 datapoints.)
We have a lot more statistics for flights IW 3309 and between Medan and Jakarta.