What months of the year are considered “in season” at Hilton Head?
I suggest you go to Kiawah island near Charleston, SC. It’s MUCH nicer than Hilton Head and so spread out that even in high season you never see throngs of people. The beach is fantastic and very wide. The temperature will be perfect for all activities in September, and less humid than in August. Also, you can visit Charleston, a lovely antebellum city with fantastic pre-civil war architecture. Savannah Georgia is an easy drive, and the restaurants on Kiawah as well as in Charleston are great. You’ll never see the kind of crowds that visit Santa Barbara. You also have a vast choice of rental options, from the main hotel to condos of all sizes, on the beach, off the beach, in the dunes, in the woods, and the wildlife (including alligators) is phenomenal.