Williamsport
September
Weather in Williamsport for September 2025
Your guide to Williamsport weather in September - trends and predictions
In general, the average temperature in Williamsport at the beginning of September is 22.6 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 17.9 °F by the end of September.
Williamsport experiences moderate rainfall in September, with an average of 9 rainy days and a total precipitation of 175 mm.
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Temperatures
Rain 🌧️
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21
Dry days
9
Rainy days
0
Snow days
22°/12°
Temperatures
10 km/h
Avg max wind
79 %
Avg humidity
Williamsport in September average weather
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| Sun. | Mon. | Tue. | Wed. | Thu. | Fri. | Sat. |
|---|---|---|---|---|---|---|
| 1  28° | 2 21° | 3  22° | 4 23° | 5 23° | 6 24° | |
| 7  17° | 8 19° | 9  23° | 10 25° | 11 25° | 12 26° | 13 26° |
| 14 28° | 15 26° | 16 25° | 17  24° | 18 23° | 19 23° | 20 25° |
| 21  19° | 22  19° | 23 16° | 24  15° | 25 18° | 26  22° | 27 19° |
| 28 19° | 29 17° | 30 15° |
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Temperatures trend during September in Williamsport
See the weather trend as well as the moving average line
September weather day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 | Fog | 28° /18° | 0.2 mm | 6 | |
| Sept. 2 | Mist | 21° /8° | 0 mm | 5 | |
| Sept. 3 | Sunny | 22° /6° | 0 mm | 6 | |
| Sept. 4 | Sunny | 23° /8° | 0 mm | 6 | |
| Sept. 5 | Mist | 23° /8° | 0 mm | 5 | |
| Sept. 6 | Fog | 24° /9° | 0.4 mm | 5 | |
| Sept. 7 | Moderate rain | 17° /6° | 9.1 mm | 4 | |
| Sept. 8 | Fog | 19° /3° | 0 mm | 4 | |
| Sept. 9 | Partly cloudy | 23° /5° | 0 mm | 6 | |
| Sept. 10 | Partly cloudy | 25° /10° | 0 mm | 6 | |
| Sept. 11 | Mist | 25° /9° | 0 mm | 6 | |
| Sept. 12 | Mist | 26° /11° | 0 mm | 6 | |
| Sept. 13 | Mist | 26° /11° | 0 mm | 6 | |
| Sept. 14 | Mist | 28° /13° | 0 mm | 6 | |
| Sept. 15 | Mist | 26° /13° | 0 mm | 6 | |
| Sept. 16 | Mist | 25° /12° | 0 mm | 5 | |
| Sept. 17 | Cloudy | 24° /13° | 0 mm | 5 | |
| Sept. 18 | Fog | 23° /12° | 0 mm | 5 | |
| Sept. 19 | Mist | 23° /14° | 0 mm | 5 | |
| Sept. 20 | Fog | 25° /14° | 0 mm | 6 | |
| Sept. 21 | Light rain | 19° /16° | 84.4 mm | 4 | |
| Sept. 22 | Overcast | 19° /17° | 5.3 mm | 4 | |
| Sept. 23 | Overcast | 16° /13° | 3.6 mm | 4 | |
| Sept. 24 | Moderate or heavy rain shower | 15° /13° | 44.1 mm | 4 | |
| Sept. 25 | Fog | 18° /15° | 14.9 mm | 4 | |
| Sept. 26 | Light rain shower | 22° /16° | 8.9 mm | 5 | |
| Sept. 27 | Light rain shower | 19° /16° | 4.1 mm | 4 | |
| Sept. 28 | Fog | 19° /17° | 0 mm | 4 | |
| Sept. 29 | Fog | 17° /15° | 0 mm | 4 | |
| Sept. 30 | Mist | 15° /14° | 0 mm | 4 | |
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Important Notice
Our weather forecast for Williamsport 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 Williamsport forecast closer to your planned date for the most up-to-date weather information.
Williamsport in September - FAQ
What are the expected maximum and minimum temperatures in Williamsport during September?
Enjoy moderate daytime temperatures of up to 22° and cooler nights around 12°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Williamsport during September?
Significant rainfall exceeding 175 mm is expected in Williamsport during September, occurring over more than 9 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Williamsport during September?
The average wind speed in Williamsport during September is 10 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Williamsport
Explore the daily rainfall trends and prepare for Williamsports September weather 💧
UV exposure in Williamsport during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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