We've been to WDW in October in 2001, 2005, 2006, 2007, and 2009. We've also stayed there in mid-September in 2002 and 2010. Our experiences with Columbus day in 2001 (very manageable due to 9/11 being a few weeks before) and 2006 (what a nightmare!) could not heve been more different. Other October trips we have been able to stay in the last couple of weeks and it has been much better, although you still will have to contend with the Food & Wine Festival.
A lot of this is subjective, but we avoid the Food & Wine Fest and the crowds that go with it when we can. I love Epcot, but hate having to deal with the restricted room and crowds with a large stroller. We would consider ourselves a bit better than average for fitness and do a lot of treadmill time in prep for the trip so we were pretty ready for pushing it, but the humidity did a number on us. We're from Chicago, so we're familliar with hot weather.
The crowds were much lighter in September of last year (9/11-9/19), but it was noticeably hotter and more humid, to the point of being a problem. If you have a member of your party that is sensitive to high heat and humidity in combination, you may want to delay your trip a few weeks.
We retire to the room for the afternoon every day to shower & recharge...I would highly recommend that. Even so, we showered 3 times daily and looked like drowned rats all of the time anyway. The pictures of us at CRT even though we'd just left the room an hour prior were pretty bad.
Even though the difference in temperature may have only been between 2-3 degrees, the difference in humidity was noticeable.
October: more crowds, Columbus Day may/will be CROWDED, weather will be a bit cooler and less humid.
September: less crowds, no Food & Wine Fest, hotter and more humid.
I hope this helps!
Dave
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