Mold assemblies for forming shaped glass articles are disclosed herein. According to one embodiment, a mold assembly may include a mold body including a mold cavity, a support base, and a plenum body extending between the mold body and the support base. When the mold assembly is heated to an average temperature of greater than or equal to about 650° C. by an overhead heating source, the temperature at the center of the mold cavity may be less than at the perimeter of the mold cavity. The difference between the temperature at the center of the mold cavity and the temperature at the perimeter of the mold cavity may be at least about 12° C.