Please be aware that Seoul has multiple airports and that these results are only for Gimpo International airport.
The best month to arrive at Seoul is November and the most expensive month to fly is August. (Average prices, based on 494 datapoints.)
The best day to arrive at Seoul is Tuesday and it would be best to avoid Sunday, as prices are on average 178.05% higher than on Tuesday. (Average prices, based on 390 datapoints.)
The cheapest airline flying to Seoul is EastarJet. They are 95% cheaper than Japan Airlines. (Average prices, based on 533 datapoints.)
At Seoul the most flights depart around 08:00. (Hourly flights, based on 611 datapoints.)
From Seoul it is on average the cheapest to fly to Busan and to Shanghai. (Average prices, based on 273 datapoints.)
From Seoul most of the flights depart to Manila, second best connected from Seoul is Tokyo. (Daily flights, based on 59 datapoints.)