chadman 154 - Southern range of yellow perch is northern, Coastal South Carolina where summertime water temps get into the low 90's. The fish are delicate at those temps and don't handle well, but make it through the dog days just fine. Not a separate species so should be well within your fishes abilities to handle your WI summers.
Like Ted said for wintertime, keep the snow off the pond and natural O2 production should be just fine in a pond that's dredged and has summertime aeration.
