No shopping suggestions, having not bought dressy clothes in a *long* time, but I agree that for Galveston, you want short sleeves on the dress or blouse; you *also* want a nice sweater or shawl that'll make you comfortable at 65F. Buildings tend to run the AC to a really cold temperature; it's not just for cooling the air, it's for reducing the 99.999% humidity to something bearable.