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 April. (Average prices, based on 2546 datapoints.)
The best day to arrive at Seoul is Wednesday and it would be best to avoid Saturday, as prices are on average 22.44% higher than on Wednesday. (Average prices, based on 2957 datapoints.)
The cheapest airline flying to Seoul is Hong Kong Express. They are 23% cheaper than Tway Airlines. (Average prices, based on 2713 datapoints.)
At Seoul the most flights depart around 23:00. (Hourly flights, based on 3101 datapoints.)
From Seoul it is on average the cheapest to fly to Shanghai and to Osaka. (Average prices, based on 2117 datapoints.)
From Seoul most of the flights depart to Tokyo, second best connected from Seoul is Kuala Lumpur. (Daily flights, based on 207 datapoints.)