September in Pittsburgh averages a daily high of 25.4°C with nights around 13.6°C. Expect roughly 8.6 wet days totalling 79.1mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Pittsburgh is May–June.
Based on EMSWORTH L D OHIO RIVER, PA US (10.6km), 1995–2024. 29 years of September data.