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 616 datapoints.)
The best day to arrive at London is Wednesday and it would be best to avoid Saturday, as prices are on average 62.14% higher than on Wednesday. (Average prices, based on 600 datapoints.)
The cheapest airline flying from London to Amsterdam is KLM. They are 26% cheaper than BA CityFlyer. (Average prices, based on 630 datapoints.)
The best time to fly is at around 16. (Average prices, based on 2646 datapoints.)