Due to multiple factors, expect to potentially pay more when booking in September. For low rates, June can be a great choice for travel to Sierra Leone. Flights to Sierra Leone from Kuala Lumpur in June are about RM 7,083 on average during June, but can be found for as low as RM 6,214.
Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Kuala Lumpur to Sierra Leone as you normally would.