Eh, as an American who's visited several major US cities, I've observed a whole lot of variation in behavior during inclement weather, partly because the US is

Eh, as an American who's visited several major US cities, I've observed a whole lot of variation in behavior during inclement weather, partly because the US is pretty big and hence pretty diverse in climate. The behavior you describe might be more common in southern California, where it doesn't rain all that often. When I was in Seattle (where it rains pretty much all the time), a lot of people didn't seem like they noticed it was raining.