Hi Denise,
You have chosen a good time to go to Walt Disney World, in my opinion. The crowds will be much lighter than in the summer months as many families will be back in school at that time. The weather will still be warm, but milder than in July or August, with temps averaging in the high 80s. Best of all, two very popular events begin in late September 2013,
Mickey's Not-So-Scary Halloween Party and
Epcot's International Food and Wine Festival.
Magic Kingdom will be the most decorated park as it is the location of Mickey's Not So Scary Halloween Party on select nights beginning on September 10. This is a special event that requires an additional ticket, but I highly recommend this amazing party, if you are able. There are so many fun and unique offerings such as a special parade, fireworks, dance parties, and trick-or-treating in the park, to name a few. The decorations are super fun and quite elaborate there at Magic Kingdom. However, at the other parks, there will be a feeling of fall, but not over the top Halloween decor.
Epcot will have fun and festive signage and topiaries as part of its theming for the Epcot International Food and Wine Festival. This event will begin on September 27, 2013. While this event doesn't require a separate admission to attend, the food/beverage booths do charge to sample these amazing delicacies from around the globe!
Have a wonderful time planning your fun and festive fall trip to Walt Disney World.
~Allison L