A long time ago, women were considered property. The purpose of a traditional ceremony was for the groom to gift enough to the bride's family that they would allow and bless the union. These days, they only continue to do it because of tradition. The church weddings, on the other hand, come from a time when Ghana's people were largely converted to Christianity. While it's common for American couples to marry in places like barns, fields, and on beaches, Ghanaian formal ceremonies only take place in churches.
In a way, it is. The traditional wedding ceremony generally takes place at dawn or before dawn, when temperatures are not so hot and light is only just beginning to peek over the horizon. Some of the traditional outfits are rather warm to wear! The "bride price" also often takes the form of land or livestock, a nod to Ghana's traditions as an agricultural society.