Welcome back!
We get this question all the time -- What's the weather like in...? This is always followed by "June," "July," "Spring Break," "Winter," or some other specific time frame. It's a fantastic question, as you should know what the weather's going to be like any time your traveling.
You need to know what type of clothes to pack --- or better yet, what not to pack. Orlando/Disney World weather can be particularly tricky, since many days (every day of some months) it rains in the afternoon -- and we don't mean a light drizzle, it can often be hurricane-like rain storms. Other months, it's 30 degrees in the morning and 75 degrees during the middle of the same day.
Due to Orlando's location in the near middle of a state that juts out into two massive bodies of water, -- the Atlantic Ocean and the Gulf of Mexico -- the area has some amazing weather patterns and conditions. Really, all you can do is act like the Boy Scouts and "Be Prepared!" Throw in that light-weight rain coat and a sweatshirt and maybe even a pair of shorts in the dead of winter.
For more detailed weather information, check out The Weather Channel's page for average Orlando weather at http://www.weather.com/weather/wxclimatology/monthly/graph/USFL0372?from=tenDay_bottomnav_undeclared. The site has some great information about Orlando weather, including average highs and lows for each month, average rainfall totals for each month, and some weather trivia about Orlando at the bottom. Even having lived in Florida for over 20 years, I would have never guessed that July is the hottest month (I would have guessed August or September -- maybe those are just the most humid. lol).
Our travel partner, DestinationsInFlorida.com, also has some great travel tips and weather information for traveling to the Disney World area at http://www.destinationsinflorida.com/traveling%20tips/index.htm