FL resident of 25+ years (live 1.5 hrs from WDW), AP and DVC. Have been to park every month so for us Sept is not as hot as summer! But that is all relative of course. Oct is busy due to Food & Wine and Not So Scary so crowd wise post Labor Day until beginning of Oct generally is better for crowds. In this area, we get our first "cold spell" the last week of Oct. Up until that time (mid-Sept to late Oct) weather is similar. Tend to be less tstorms in Oct.