We go in the late fall, never gone in the summer, but my understanding is that the hotel is still fully running, as is everything else on the island (except the fireworks and turtle nesting). they still run lots of activities, just don't be surprised if they have fewer participants at an activity than they do in the summer. Have fun-from what I've heard, late September is a great time at HHI. Warm enough for swimming, but far less busy.