we visited 1st week of oct last year (& will again this year

), mostly for the F&WF.
weather was nice, warm, but not hot, & not an unreasonaable amount of rain (we've given up trying to forecast based on the entire "hurricane season" thing, btw ~ during trips in march, april, may, june, august, sept, oct, & early november, the weather has been almost identical, extremes being a june trip with daily, mostly heavy rain, & an oct trip that temps went into the low 30's

).
for oct, we pack clothes based on temps in the low 80's, with a sweater/sweatshirt for chillier eves. poncho or rainjacket is an absolute (the only guarantee being that it
will rain if you don't have one

).
we found the parks especially crowded on the weekends (a quick visit to EPCOT on a saturday late afternoon led to an even quicker exit

lol)...the other parks were also crowded but not to the extent of the F&WF host. we wound up relaxing at the resort, outlet shopping, etc on the weekends to avoid the masses (literally wall-to-wall ppl at times).
just stay flexible, & alter your plans based on crowd levels, weather, etc, & you'll have a great time
