It's usually off and on scattered showers. We have experienced all day rain, but that was in January and September. At least this time of year, you should be able to go out in a poncho and be fine. In the winter, it's just too cold, IMO, to do that when it's raining.
Here's a post I made on a similar thread last week about some things we enjoy doing on washout days. This post was for a couples only trip, but I'll add a few things if you're bringing kids.
Rainy Day things:
* Check out the Rainy Day Calvalcade at Magic Kingdom (if they cancel Festival of Fantasy due to the weather) Also there's a lot of attractions at MK indoors.
* Go to Disney Springs Goofy's Candy store and make your own Mickey rice krispie or marshmallow snack
* Go to Disney Springs to the
Lego store
* If adults only, tour the Monorail resorts and go on a unofficial lounge hop, sampling some great apps and drinks (CR- CA Grill Lounge, Wave Lounge, Outer Rim Lounge. Poly- Tambu Lounge and Trader Sams. GF- Mizner's Lounge and Citricos Lounge) Or, if family trip, do the same hop, but make it a Monorail Resorts treats hop! Cupcakes at CR, Dole Whip at Poly, and something extravagant at GF!
* If you're into reading, perhaps relax by the giant fireplace at Wilderness Lodge with a good book
* Epcot Future World is a great park on rainy days due to so many indoor attractions. Despite this, it's our experience that it is still practically empty on rainy days.
* If the budget allows, make a trip to GFs Senses Spa.
* Go to Port Orleans Riverside and enjoy Yeehaw Bob's show at the River Roost Lounge (I believe kids are allowed at this, but be sure to double check!)
* Attend the Hoop Dee Doo Revue
* When we took kids and stayed at BLT, they had a craft/activity room that the kids loved! Most of the stuff, including make your own bead necklace, was free.
I hope it all works out! It's disappointing when the weather doesn't cooperate, but try to remember you're on vacation and brainstorm other things to do that perhaps you've never even done before.