i'm in south Florida and heading to Disney later today, and I can tell you the past week has been amazing here, so nice and cool. You will be fine with Capri's...i went to Disney for Labor Day weekend and was fine in the all day and wearing capri's.
With that being said, the past week has been lows in the 60's and highs in the mid 80's..not cold, but cooler than the evil summer months here. The heat of the day is really around 1pm-4pm, and that is when it will heat up if at all there.
You can never really predict the weather in Florida, unless it is summer then it is hot, humid and a chance of rain everyday.
check the local news station weather report, wesh.com