Flight Juanda International Airport departs from Surabaya Juanda International Airport at 13:00 and arrives at Jakarta Soekarno–Hatta International Airport at 14:30.
The flighttime is about 1h 30m. The distance travelled ("as the bird flies"): 682 Km. So the average speed is roughly 455 Km.
The best month to arrive at Surabaya is February and the most expensive month to fly is September. (Average prices, based on 1850 datapoints.)
We have a lot more statistics for flights IU 345 and between Surabaya and Jakarta.