Please be aware that Kuala Lumpur and Seoul has multiple airports and that these results are for all airports serving the city.
The best month to fly between Kuala Lumpur and Seoul is May and the most expensive month to fly is September. (Average prices, based on 284 datapoints.)
The best day to arrive at Kuala Lumpur is Saturday and it would be best to avoid Friday, as prices are on average 126.98% higher than on Saturday. (Average prices, based on 284 datapoints.)