Please be aware that Yogyakarta has multiple airports and that these results are for all airports serving the city.
The best month to fly between Yogyakarta and Bandar Lampung is October and the most expensive month to fly is June. (Average prices, based on 1790 datapoints.)
The best day to arrive at Yogyakarta is Tuesday and it would be best to avoid Sunday, as prices are on average 18.17% higher than on Tuesday. (Average prices, based on 1785 datapoints.)