Please be aware that Istanbul has multiple airports and that these results are for all airports serving the city.
The best month to fly between Istanbul and Ankara is January and the most expensive month to fly is April. (Average prices, based on 733 datapoints.)
The best day to arrive at Istanbul is Sunday and it would be best to avoid Thursday, as prices are on average 383.03% higher than on Sunday. (Average prices, based on 735 datapoints.)