Please be aware that London has multiple airports and that these results are for all airports serving the city.
The best month to fly between London and Amsterdam is March and the most expensive month to fly is July. (Average prices, based on 972 datapoints.)
The best day to arrive at London is Wednesday and it would be best to avoid Tuesday, as prices are on average 123.03% higher than on Wednesday. (Average prices, based on 869 datapoints.)