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 Singapore is June and the most expensive month to fly is December. (Average prices, based on 353 datapoints.)
The best day to arrive at Yogyakarta is Saturday and it would be best to avoid Tuesday, as prices are on average 62.6% higher than on Saturday. (Average prices, based on 353 datapoints.)