Allentown (PA)
September
Weather in Allentown, Pennsylvania for September 2026
Your guide to Allentown weather in September - trends and predictions
In general, the average temperature in Allentown at the beginning of September is 24.3 °F. As the month progressed, temperatures tended to noticeably cool down, reaching an average of 22 °F by the end of September.
Allentown experiences moderate rainfall in September, with an average of 9 rainy days and a total precipitation of 74.3 mm.
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Temperatures
Rain 🌧️
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21
Dry days
9
Rainy days
0
Snow days
23°/13°
Temperatures
15 km/h
Avg max wind
74 %
Avg humidity
Allentown Weather September
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Temperatures trend during September in Allentown
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September weather in Allentown day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Moderate or heavy rain shower | 25° /16° | 2.7 mm | 6 | |
| Sept. 2 |  Overcast | 24° /14° | 0 mm | 6 | |
| Sept. 3 |  Sunny | 23° /10° | 0 mm | 6 | |
| Sept. 4 | Sunny | 25° /11° | 5 mm | 6 | |
| Sept. 5 | Sunny | 27° /14° | 11.9 mm | 7 | |
| Sept. 6 | Overcast | 26° /15° | 0 mm | 6 | |
| Sept. 7 | Moderate or heavy rain shower | 20° /12° | 14.8 mm | 5 | |
| Sept. 8 | Sunny | 22° /9° | 0 mm | 6 | |
| Sept. 9 |  Partly cloudy | 23° /9° | 0 mm | 6 | |
| Sept. 10 | Sunny | 23° /10° | 0 mm | 6 | |
| Sept. 11 | Sunny | 25° /11° | 0 mm | 6 | |
| Sept. 12 | Sunny | 25° /13° | 0 mm | 7 | |
| Sept. 13 | Sunny | 25° /14° | 18 mm | 6 | |
| Sept. 14 | Partly cloudy | 29° /14° | 0 mm | 7 | |
| Sept. 15 | Partly cloudy | 26° /14° | 0 mm | 6 | |
| Sept. 16 | Overcast | 24° /12° | 0 mm | 5 | |
| Sept. 17 | Overcast | 22° /14° | 0 mm | 5 | |
| Sept. 18 |  Patchy rain possible | 24° /16° | 0.2 mm | 6 | |
| Sept. 19 | Overcast | 27° /15° | 3.7 mm | 6 | |
| Sept. 20 | Overcast | 22° /14° | 0 mm | 5 | |
| Sept. 21 | Overcast | 22° /14° | 0 mm | 5 | |
| Sept. 22 | Overcast | 23° /14° | 0 mm | 5 | |
| Sept. 23 | Moderate or heavy rain shower | 22° /15° | 7.8 mm | 5 | |
| Sept. 24 | Overcast | 23° /16° | 20 mm | 6 | |
| Sept. 25 | Moderate or heavy rain shower | 21° /16° | 35.2 mm | 5 | |
| Sept. 26 | Moderate rain at times | 24° /17° | 8.1 mm | 6 | |
| Sept. 27 | Moderate or heavy rain shower | 22° /14° | 2.5 mm | 5 | |
| Sept. 28 | Moderate rain at times | 22° /16° | 16.8 mm | 5 | |
| Sept. 29 | Patchy rain possible | 21° /14° | 0.3 mm | 5 | |
| Sept. 30 |  Mist | 21° /14° | 0 mm | 5 | |
| Next | |||||
Important Notice
Our weather forecast for Allentown 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 Allentown forecast closer to your planned date for the most up-to-date weather information.
Change Month
Allentown in September - FAQ
What are the expected maximum and minimum temperatures in Allentown during September?
Enjoy moderate daytime temperatures of up to 23° and cooler nights around 13°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Allentown during September?
Moderate rainfall is anticipated in Allentown during September, with a total of 74.3 mm spread over approximately 9 days. Considering plans for rainy days is advisable.
What are the typical wind conditions in Allentown during September?
The average wind speed in Allentown during September is 15 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Allentown
Explore the daily rainfall trends and prepare for Allentowns September weather 💧
UV exposure in Allentown during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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