Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Belfast to Douala as you normally would.
Located just 2.6 mi from the city center, Douala is the airport most travelers will use when flying to Douala from Belfast. Booking flights from Belfast to Douala (DLA) should be relatively easy as there are 0 daily inbound flights from Belfast from 0 different airlines.