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 Sandakan is September and the most expensive month to fly is June. (Average prices, based on 226 datapoints.)
The best day to arrive at Kuala Lumpur is Thursday and it would be best to avoid Wednesday, as prices are on average 110.9% higher than on Thursday. (Average prices, based on 226 datapoints.)