From having lived there....expect 90 & 90. 90 degrees and 90% humidity. There will typically be a thunderstorm each day ~3-5 pm.
IF a weather front is coming through, that's what will change the overall picture. A low front coming thorough will likely create longer lasting, and sometimes very intense rains. Back side of these fronts though are usually a bit cooler (Brrrrrr.........mid to high 80s)
As for crowds....expect clowns to the left of you, jokers to the right....and lots of them. Beware of strollers, as they can leave permanent scars on your shins. For everyone else's sake be sure to wear deoodorant and pray that the big hairy guy in front of you in the Space Mountian line did the same.