Pittsburgh Weather in September

Pittsburgh at the confluence of three rivers has a full humid continental climate shaped dramatically by its river valley topography. The city's steep hills and three rivers (Ohio, Monongahela, Allegheny) create dozens of distinct microclimates between hilltop neighborhoods and valley bottoms. Fog and overcast skies are common and the city historically had severe air pollution (now dramatically improved).

Excellent shoulder season — warm with fewer tourists in many destinations.