our last (and final) summer visit - July 2003, it rained every day, sometimes for an hour, sometimes for 3 or 4 hours in the afternoon.
1. it cools down things, which is greatly appreciated in the summertime!
2. it thins out the crowds - seperates the men from the boys - so to speak.
What's that mean - A GREAT TIME TO VISIT THE PARKS! Yes, you get a little wet, as the ponchos (Mickey is on them!) don't cover everything, and some of the rides will close if thunder/lightning is in the area, but you can have a good time. Go enjoy the parks, that's what we did.