Last year we went the last week of Sept. (our 1st WDW trip). Going again, same time, this year!
It was hot and it was humid, but not terrible. It rained for a short time everyday. I see you're from NY. Long Island or Upstate? If Long island, the weather (hopefully) will be like it was earlier in the week, but not as cool at night.
Have a great trip!
Shelby