I think if you add ponchos and umbrellas for sale at gift shops peeps could buy them for rainy weather or wear the ponchos on water rides like actual people do in real theme parks.
Umbrellas are in the game and used when it's raining (even peeps in swimwear are using them). Ponchos would be a nice addition (rain and water rides), but I guess they wouldn't wear them on rides in general...
