Please be aware that London has multiple airports and that these results are only for Heathrow Airport.
The best month to arrive at London is November and the most expensive month to fly is September. (Average prices, based on 1914 datapoints.)
The best day to arrive at London is Tuesday and it would be best to avoid Sunday, as prices are on average 48.04% higher than on Tuesday. (Average prices, based on 1891 datapoints.)
The cheapest airline flying to London is Aer Lingus. They are 87% cheaper than Virgin Atlantic. (Average prices, based on 2128 datapoints.)
At London the most flights depart around 18:00. (Hourly flights, based on 2663 datapoints.)
From London it is on average the cheapest to fly to Dublin and to Amsterdam. (Average prices, based on 532 datapoints.)
From London most of the flights depart to Amsterdam, second best connected from London is Frankfurt. (Daily flights, based on 167 datapoints.)