Conditions in late September

I'm chompin' at the bit, so anxious to get down there that I'm working on a trip in late September in addition to our usual March trip. I know that's kind of the end of the rainy season, so I'm wondering if much changes around there during that early fall stretch.
Specifically, are most of the restaurants open (assuming COVID is less restrictive by then)? How about water sports rentals and massage tents along the beach?