Please be aware that Seoul has multiple airports and that these results are for all airports serving the city.
The best month to arrive at Seoul is July and the most expensive month to fly is October. (Average prices, based on 578 datapoints.)
The best day to arrive at Seoul is Monday and it would be best to avoid Saturday, as prices are on average 24.17% higher than on Monday. (Average prices, based on 2840 datapoints.)
The cheapest airline flying to Seoul is Jeju Air. They are 80% cheaper than Cathay Pacific. (Average prices, based on 693 datapoints.)
At Seoul the most flights depart around 22:00. (Hourly flights, based on 1403 datapoints.)
From Seoul it is on average the cheapest to fly to Manila and to Kuala Lumpur. (Average prices, based on 247 datapoints.)
From Seoul most of the flights depart to Kuala Lumpur, second best connected from Seoul is Tokyo. (Daily flights, based on 333 datapoints.)