The best month to fly between Surabaya and Singapore is October and the most expensive month to fly is June. (Average prices, based on 519 datapoints.)
The best day to arrive at Surabaya is Wednesday and it would be best to avoid Tuesday, as prices are on average 19% higher than on Wednesday. (Average prices, based on 17621253 datapoints.)
The best time to fly is at around 9. (Average prices, based on 7255 datapoints.)