We have lots of family in Hampden, and stay at Pumpkin Patch a few w/ends every year. As others have said, there are shaded sites available. They accept Passport America except for July/August, so we find it to be both economical and a great value. I/We appreciate the exceptional cleanliness/maintenance of the whole facility. It's also very popular with small caravan groups.
About 25 miles south of Bangor there is another nice CG in Palmyra. They also own the golf course, and offer RV/golf packages Another great value.