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 April and the most expensive month to fly is March. (Average prices, based on 620 datapoints.)
The best day to arrive at Seoul is Tuesday and it would be best to avoid Friday, as prices are on average 175.39% higher than on Tuesday. (Average prices, based on 648 datapoints.)
The cheapest airline flying to Seoul is Jin Air. They are 90% cheaper than Asiana Airlines. (Average prices, based on 711 datapoints.)
At Seoul the most flights depart around 23:00. (Hourly flights, based on 756 datapoints.)
From Seoul it is on average the cheapest to fly to Shanghai and to Osaka. (Average prices, based on 210 datapoints.)