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 November and the most expensive month to fly is August. (Average prices, based on 1824 datapoints.)
The best day to arrive at London is Wednesday and it would be best to avoid Saturday, as prices are on average 45.07% higher than on Wednesday. (Average prices, based on 2207 datapoints.)
The cheapest airline flying from London to Amsterdam is KLM. They are 16% cheaper than British Airways. (Average prices, based on 1840 datapoints.)
The best time to fly is at around 16. (Average prices, based on 3153 datapoints.)