Flight Kualanamu International Airport departs from Medan Kualanamu International Airport at 08:40 and arrives at Jakarta Soekarno–Hatta International Airport at 12:10.
The flighttime is about 3h 30m. The distance travelled ("as the bird flies"): 895 Km. So the average speed is roughly 256 Km.
The best month to arrive at Medan is January and the most expensive month to fly is April. (Average prices, based on 369 datapoints.)
We have a lot more statistics for flights JT 299 and between Medan and Jakarta.