I just got home from WDW. I was there 10-20 September and the average temperature was 86-90 degrees, with high humidity, especially after all the rain on Saturday and Sunday. I took jeans, but never wore them. I lived in shorts and tee shirts, and for a couple of days, a poncho.
I suggest packing shorts, but also 1 or 2 pairs of jeans or long pants and a light jacket, just in case the weather cools down.
FYI - I have also been to WDW in late September, October and early November, and except for an occasional cool evening, I lived in shorts.
Hope this helps. Have fun.
Posted on Sep 21, 2000, 5:50 PM from IP address 205.188.199.137