Please be aware that London has multiple airports and that these results are for all airports serving the city.
The best month to arrive at London is November and the most expensive month to fly is May. (Average prices, based on 1609 datapoints.)
The best day to arrive at London is Tuesday and it would be best to avoid Saturday, as prices are on average 60.83% higher than on Tuesday. (Average prices, based on 398 datapoints.)
The cheapest airline flying to London is Aer Lingus. They are 91% cheaper than United Airlines. (Average prices, based on 1748 datapoints.)
At London the most flights depart around 07:00. (Hourly flights, based on 2831 datapoints.)
From London it is on average the cheapest to fly to Madrid and to Amsterdam. (Average prices, based on 197 datapoints.)
From London most of the flights depart to Amsterdam, second best connected from London is Valencia. (Daily flights, based on 429 datapoints.)