We'll be there on the 4th this year, our 1st time during that time of year. We have done Christmas and Easter before, so we're prepared for the crowds. The heat and humidity is our biggest concern.
Remember that the 4th is a Sunday, EE for MK. So, if you plan to do MK that day - go as early as possible and PLAN, PLAN, PLAN! If there are rides that you want to do, get them done 1st! No shopping, No characters, No shows, etc...you can do those later.
My plan is to go straight to Dumbo, Grab Fast Pass for Pooh, Indy Cars, ride Pooh, Snow White, Grab FP for Peter Pan, see Philharmagic, ride Peter Pan and then...we're outta there! We have a PS at Chef Mickey's for 11:15. We are seeing WISHES from the Grand One out in the Lagoon (WOOHOO!).
We followed a similar plan on Easter Sunday a few years ago and it worked great! We finished what we planned by 11 am, had some lunch and sat in a shady spot on Main St. (for 2 hrs.) to reserve a spot for the parade. I expect the 4th will be much hotter than Easter, though, so we'll save the parade for another day.
Anyhow, my advice...Go EARLY, PLAN & Use FAST PASS! Oh, and sunscreen and Mister Fans, or something else to keep cool!
