Katahdin: How late in the Season?

I know that MANY different variables go into making a good (safe) hike on Katahdin. I have a week off in early October, what are the chances of the weather being coperative? What is the weather like in general at lower elevations in early October? We were in Millinocket in mid-May and all the trails to the top were still closed. We may also spend some time in Acadia on the trip, when is the height of the fall tourist season, I really don't want to fight the crowds.

thanks all
j