Sorry if this has alreadly been said....I didn't have time to read the entire thread.
I have gone most of my 15 trips in the last week of February. Shorts were pretty much all I needed but I did have pants with me because it can get pretty chilly. I think in 2002 there was a cold air mass that came down from Canada (I haven't forgiven them for that yet) and one day I went to Disney/MGM and everyone, including myself was wearing a jacket. The wind was really cold! The next day, shorts and t's.
I know it has been stated that it can be pretty unpredictable that month but for the most part, if you came in from a cold weather area, light wear is what you will need.
Layered is a good idea. I've cleaned frost off my car in the morning and run the air conditioning in the afternoon. Gotta love it!