When we travel, rain or shine, our visits to parks, historic locations, museums, and other locations continue. Travelers get out umbrellas, rain coats, and other foul weather gear and trudge on.
Unfortunately, when it rains, many travelers leave their cameras at the hotel, or at best, put them in their pockets, except for indoor photos. I'm well aware that even inexpensive DSLR cameras and lenses aren't “cheap,” and if they're caught in a storm, they could be ruined. Not only would that be expensive, you wouldn't have their use for the remainder of your trip.