Weather in Pittsburgh in September 2025
- September is usually the wettest month of the year in Pittsburgh;
Average weather
Average temperature in Pittsburgh in September
The temperature in September is +25°C on average, with a range between a maximum of +33°C during the day and a minimum of +9°C at night.
The average maximum temperature goes down 8% by the end of the month, compared with the beginning of the month, from +27°C to +25°C.
Is Pittsburgh warm or cold in September?
Pittsburgh is typically warm in September.
Maximum temperatures go down compared to the previous month from +28°C to +24°C. The minimum temperature also goes down from +18°C to +14°C.
It’s generally warm, but pack a long-sleeve shirt for evenings.
Take a look at how September is compared to other months in Pittsburgh:
Climate in Pittsburgh in September
| August | September | October | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +28°C | +24°C | +18°C | ||||
| Min. temperature | ||||||
| +5°C | +2°C | -4°C | ||||
| Max. temperature | ||||||
| +37°C | +35°C | +32°C | ||||
| Rainfall | ||||||
| 93 mm | 98 mm | 89 mm | ||||
| Wind | ||||||
| 2 m/s | 2 m/s | 2 m/s | ||||
| Humidity | ||||||
| 76% | 77% | 75% | ||||
| Air pressure | ||||||
| 1016 HPa | 1017 HPa | 1017 HPa | ||||
| Sunny days | ||||||
| 5 | 8 | 7 | ||||
| Cloudy days | ||||||
| 7 | 8 | 9 | ||||
| Rainy days | ||||||
| 18 | 15 | 15 | ||||
| Snowy days | ||||||
| 0 | 0 | 0 | ||||
September weather is still as ok as in August. It’s getting colder in September. From +28°C in the day, the average maximum temperature lowers to +24°C. Prepare for more rain. Average rainfall goes from 93 mm to 98 mm. Humidity rises from 76% to 77%. The average wind speed doesn’t change much during September, staying around 2 m/s. The good news is there are likely to be more sunny days in September, from 5 to 8.
October brings much the same weather, it remains ok.
Wind
The average wind speed is 2 m/s getting up to 3 m/s which is a light breeze; barely moving the tree leaves.
The average wind speed in Pittsburgh is gradually decreasing during September, going from 2 m/s to 1 m/s over the course of the month.
Rain
How was the weather last September in Pittsburgh?
Climate Change over Years
The climate in Pittsburgh in September has not changed much over the last 43 years.
The average temperature was the lowest in 1979 (+15°C) and the highest in 2012 (+19°C). The driest year was 1988 with only 782 mm of rainfall, and the wettest year was 2019 with 2006 mm.
FAQ
Is September a good time to visit Pittsburgh?
Can you sunbathe in Pittsburgh in September?
Is Pittsburgh rainy in September?
Is it sunny in Pittsburgh in September?
Other cities in USA
Monthly weather in Pittsburgh
Source of the data
For this page, we’ve looked at the typical weather in Pittsburgh, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.
