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 Amsterdam is February and the most expensive month to fly is August. (Average prices, based on 920 datapoints.)
The best day to arrive at Istanbul is Wednesday and it would be best to avoid Saturday, as prices are on average 89.44% higher than on Wednesday. (Average prices, based on 1054 datapoints.)
The best time to fly is at around 12. (Average prices, based on 1707 datapoints.)