Flight Soekarno–Hatta International Airport departs from Jakarta Soekarno–Hatta International Airport at 09:00 and arrives at Surabaya Juanda International Airport at 10:40.
The flighttime is about 1h 40m. The distance travelled ("as the bird flies"): 682 Km. So the average speed is roughly 409 Km.
The best month to arrive at Jakarta is December and the most expensive month to fly is July. (Average prices, based on 3951 datapoints.)
We have a lot more statistics for flights EY 8138 and between Jakarta and Surabaya.