Please be aware that Kuala Lumpur has multiple airports and that these results are for all airports serving the city.
The best month to fly between Kuala Lumpur and Sibu is June and the most expensive month to fly is April. (Average prices, based on 231 datapoints.)
The best day to arrive at Kuala Lumpur is Wednesday and it would be best to avoid Monday, as prices are on average 333.82% higher than on Wednesday. (Average prices, based on 231 datapoints.)