Allegheny County (Pittsburgh)
September
Weather in Allegheny County, Pennsylvania for September 2027
Your guide to Allegheny County weather in September - trends and predictions
In general, the average temperature in Allegheny County at the beginning of September is 27.6 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 22.1 °C by the end of September.
Allegheny County experiences moderate rainfall in September, with an average of 9 rainy days and a total precipitation of 144.3 mm.
Is September a good time to visit Allegheny County? check out the best time to travel to Allegheny County page.
✨ Is September a good time to visit Allegheny County? – Ask the AI Weatherman
Temperatures
Rain 🌧️
More
21
Dry days
9
Rainy days
0
Snow days
25°/15°
Temperatures
12 km/h
Avg max wind
71 %
Avg humidity
Allegheny County Weather September
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Temperatures trend during September in Allegheny County
See the weather trend as well as the moving average line
September weather in Allegheny County day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Sunny | 28° /16° | 0 mm | 6 | |
| Sept. 2 | Sunny | 28° /15° | 0 mm | 7 | |
| Sept. 3 | Sunny | 30° /16° | 0.1 mm | 7 | |
| Sept. 4 |  Thundery outbreaks possible | 27° /17° | 15.6 mm | 6 | |
| Sept. 5 |  Partly cloudy | 29° /17° | 0.1 mm | 7 | |
| Sept. 6 |  Moderate rain | 28° /16° | 16.3 mm | 7 | |
| Sept. 7 |  Light rain | 24° /14° | 3 mm | 6 | |
| Sept. 8 |  Overcast | 24° /12° | 0 mm | 6 | |
| Sept. 9 |  Patchy rain possible | 27° /14° | 2.4 mm | 5 | |
| Sept. 10 | Moderate rain | 27° /15° | 11.7 mm | 5 | |
| Sept. 11 | Overcast | 27° /15° | 0.1 mm | 6 | |
| Sept. 12 | Light rain | 28° /15° | 4.7 mm | 6 | |
| Sept. 13 | Light rain | 26° /15° | 4.4 mm | 5 | |
| Sept. 14 | Sunny | 25° /14° | 0.1 mm | 7 | |
| Sept. 15 | Sunny | 26° /13° | 0 mm | 6 | |
| Sept. 16 | Overcast | 25° /14° | 0.5 mm | 5 | |
| Sept. 17 | Light rain | 22° /16° | 6.1 mm | 4 | |
| Sept. 18 |  Patchy light rain with thunder | 23° /15° | 0.3 mm | 5 | |
| Sept. 19 | Patchy rain possible | 24° /15° | 1 mm | 5 | |
| Sept. 20 | Light rain | 25° /14° | 9.8 mm | 5 | |
| Sept. 21 |  Moderate or heavy rain shower | 25° /15° | 9.8 mm | 5 | |
| Sept. 22 | Patchy rain possible | 24° /15° | 2.1 mm | 5 | |
| Sept. 23 | Moderate rain | 22° /15° | 24.5 mm | 4 | |
| Sept. 24 | Light rain | 21° /14° | 8.1 mm | 5 | |
| Sept. 25 | Light rain | 22° /14° | 5.6 mm | 5 | |
| Sept. 26 | Overcast | 22° /14° | 0.8 mm | 5 | |
| Sept. 27 | Patchy rain possible | 23° /14° | 1.9 mm | 4 | |
| Sept. 28 | Light rain shower | 21° /14° | 2.4 mm | 4 | |
| Sept. 29 |  Fog | 23° /15° | 0.7 mm | 4 | |
| Sept. 30 | Moderate rain | 23° /14° | 12.2 mm | 4 | |
| Next | |||||
Important Notice
Our weather forecast for Allegheny County in September is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Allegheny County forecast closer to your planned date for the most up-to-date weather information.
Change Month
Allegheny County in September - FAQ
What are the expected maximum and minimum temperatures in Allegheny County during September?
During September, expect a variety of temperatures with highs around 25° and lows near 15°, suitable for diverse activities and preferences.
How much rainfall should be expected in Allegheny County during September?
Significant rainfall exceeding 144.3 mm is expected in Allegheny County during September, occurring over more than 9 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Allegheny County during September?
The average wind speed in Allegheny County during September is 12 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Allegheny County
Explore the daily rainfall trends and prepare for Allegheny Countys September weather 💧
Typically, Allegheny County has 9 rainy days in September with a total of 144.3 mm of rainfall.
UV exposure in Allegheny County during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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