Well, that is a very pretty area, no question about it. There are lots of beach towns farther east, which should be less humid - Ocean City, MD, Dewey and Bethany Beach, Lewes, DE, . St. Michaels is amazing too. That's where they filmed a lot of Wedding Crashers. Seahawk lives in a super nice area too, but I don't know if there's anything to do there other than shoot on his farm
. My favorite area near DC is Middleburg, VA, which is horse country. I doubt your daughter is going to get much sightseeing in during her Plebe Summer. It's gonna be tough no matter what climate she's used to.