Fall in Pennsylvania is nothing short of stunning. Pennsylvania is lucky enough to have some of the best fall foliage in the entire country, thanks to its many forests, mountains, and beautiful state parks. When Is Peak Foliage in PA? According to the Pennsylvania Department of Conservation and Natural Resources, the northern part of the state will see peak foliage first, typically around early to mid-October. Central Pennsylvania will follow in mid to late October, while the southern regions — including the Philadelphia area — will likely peak in late October to early November.