The coldest the water has ever been when I was there was 77 F and that was only for a day or two when a northern had come down and stayed down last year. In my experience, the water temp is usually hovering around 81 F. That is also what my computer registered for the 3 weeks over Xmas and NY. I think at depth it got to 79 F a couple of times.
I was wearing a full 3 mm and got chilled once in a while but that is mostly because it doesn't fit me properly, as well as, diving every day the chill effects are cumulative. I'm sure that with a good fit, I'd have been right comfey.