Please be aware that New York has multiple airports and that these results are for all airports serving the city.
The best month to fly between New York and Amsterdam is July and the most expensive month to fly is January. (Average prices, based on 350 datapoints.)
The best day to arrive at New York is Tuesday and it would be best to avoid Thursday, as prices are on average 56.11% higher than on Tuesday. (Average prices, based on 350 datapoints.)
