Please be aware that Yogyakarta has multiple airports and that these results are only for Adisutjipto International Airport.
The best month to arrive at Yogyakarta is October and the most expensive month to fly is June. (Average prices, based on 451631 datapoints.)
The best day to arrive at Yogyakarta is Monday and it would be best to avoid Friday, as prices are on average 17.47% higher than on Monday. (Average prices, based on 515264 datapoints.)