Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Thunder Bay to Barcelona as you normally would.
For a flight from Thunder Bay to Barcelona, you will be flying from Thunder Bay. Thunder Bay (YQT) is just 5.6 km from the centre of the city. Thunder Bay is the only Thunder Bay airport and it handles 0 outbound flights to Barcelona per day. 1 airline has flights to Barcelona from Thunder Bay on a regular basis.