Please be aware that Seoul has multiple airports and that these results are only for Incheon International Airport.
The best month to arrive at Seoul is November and the most expensive month to fly is October. (Average prices, based on 3372 datapoints.)
The best day to arrive at Seoul is Wednesday and it would be best to avoid Saturday, as prices are on average 13.03% higher than on Wednesday. (Average prices, based on 3590 datapoints.)
The cheapest airline flying to Seoul is Air China. They are 35% cheaper than Malindo Air. (Average prices, based on 3492 datapoints.)
At Seoul the most flights depart around 23:00. (Hourly flights, based on 3684 datapoints.)
From Seoul it is on average the cheapest to fly to Guangzhou and to Ho Chi Minh City. (Average prices, based on 444 datapoints.)
From Seoul most of the flights depart to Tokyo, second best connected from Seoul is Bangkok. (Daily flights, based on 125 datapoints.)