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 January. (Average prices, based on 2316 datapoints.)
The best day to arrive at Seoul is Wednesday and it would be best to avoid Saturday, as prices are on average 28.72% higher than on Wednesday. (Average prices, based on 3312 datapoints.)
The cheapest airline flying to Seoul is Hong Kong Express. They are 40% cheaper than Air Seoul. (Average prices, based on 2422 datapoints.)
At Seoul the most flights depart around 23:00. (Hourly flights, based on 2611 datapoints.)
From Seoul it is on average the cheapest to fly to Shanghai and to Hong Kong. (Average prices, based on 1377 datapoints.)
From Seoul most of the flights depart to Tokyo, second best connected from Seoul is Kuala Lumpur. (Daily flights, based on 130 datapoints.)
