Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Swansea to Belfast as you normally would.
Swansea Fairwood Comm (SWS) is the airport you will fly out of if you book a flight from Swansea to Belfast. You should not have trouble finding flights to Belfast from Fairwood Comm; the airport handles an average of 0 outbound flights to Belfast per day. You should also have plenty of airline options to choose from since 0 airlines have flights from the Swansea airport to Belfast. It is only a 5.4 mi journey to Fairwood Comm (SWS) from Swansea’s city centre.