We went up WDW in June. I was expecting 20 minute showers but it rained quite a bit every day with thunderstorms and lightening. Are there any months with absolutely no rain? Although this might sound like a crazy thing I live in southern Califirnia where we literally have no rain all summer and usually from May-September. It's just dry and hit which is way better than rainy, humid, and hot.
It did not rain in the morning but it rained all afternoon usually. We are late risers so although we had fun it was a little inconvenient. (Btw, staying on Pacific time worked wonderfully for us when we got bank home to work and camp. I had no migraines either. I usually get them when I try to adjust to new time zones. They tend to last a couple of weeks.)