Bags get wet like this in most "wet-weather" cities. Back in the day when I had to check a bag, it was covered in snow(!!) in ABQ and GEG, soaked (to the point where I could wring water out of some clothes) in MDW, LGA, PDX, RDU etc.

Unfortunately even with covers, things get wet. Heck, my bag gets wet when I fly QX and gate check the thing.