Johnstown (PA)
September
Weather in Johnstown, Pennsylvania for September 2026
Your guide to Johnstown weather in September - trends and predictions
So far, September 2026 in Johnstown shows a warmer trend than usual by 3.9 °F.
The forecast for the next days in Johnstown predicts temperatures to be around 23 °F, close to the historical average.
In general, the average temperature in Johnstown at the beginning of September is 24.3 °F. As the month progressed, temperatures tended to noticeably cool down, reaching an average of 21.7 °F by the end of September.
Johnstown experiences moderate rainfall in September, with an average of 7 rainy days and a total precipitation of 217.4 mm.
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Temperatures
Rain 🌧️
More
23
Dry days
7
Rainy days
0
Snow days
21°/13°
Temperatures
11 km/h
Avg max wind
78 %
Avg humidity
Johnstown Weather September
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Temperatures trend during September in Johnstown
See the weather trend as well as the moving average line
September weather in Johnstown day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Overcast | 26° /14° | 0 mm | 8 | |
| Sept. 2 | Overcast | 27° /15° | 0 mm | 9 | |
| Sept. 3 | Overcast | 27° /16° | 12.3 mm | 5 | |
| Sept. 4 |  Light rain shower | 23° /16° | 12.3 mm | 5 | |
| Sept. 5 |  Fog | 25° /16° | 2.8 mm | 4 | |
| Sept. 6 |  Heavy rain | 22° /12° | 11.4 mm | 5 | |
| Sept. 7 | Fog | 20° /10° | 0 mm | 5 | |
| Sept. 8 | Overcast | 18° /6° | 0 mm | 8 | |
| Sept. 9 | Overcast | 26° /16° | 0 mm | 4.6 | |
| Sept. 10 | Light rain shower | 24° /17° | 7 mm | 1.1 | |
| Sept. 11 | Light rain shower | 24° /15° | 6.1 mm | 6.9 | |
| Sept. 12 | Light rain shower | 22° /15° | 2.5 mm | 5.4 | |
| Sept. 13 | Fog | 24° /16° | 2.6 mm | 5 | |
| Sept. 14 | Fog | 25° /20° | 0 mm | 6 | |
| Sept. 15 | Light rain shower | 25° /18° | 10.5 mm | 5 | |
| Sept. 16 | Patchy rain possible | 21° /12° | 1.6 mm | 5 | |
| Sept. 17 |  Sunny | 20° /11° | 0 mm | 6 | |
| Sept. 18 | Sunny | 24° /16° | 0 mm | 6 | |
| Sept. 19 | Fog | 21° /7° | 1.8 mm | 4 | |
| Sept. 20 | Patchy rain possible | 14° /7° | 0.4 mm | 4 | |
| Sept. 21 | Mist | 28° /10° | 1.4 mm | 7 | |
| Sept. 22 | Overcast | 21° /12° | 0.8 mm | 5 | |
| Sept. 23 | Light rain shower | 21° /16° | 89.5 mm | 2 | |
| Sept. 24 |  Moderate or heavy rain shower | 23° /16° | 74.1 mm | 1 | |
| Sept. 25 |  Light rain | 20° /16° | 6.7 mm | 2 | |
| Sept. 26 | Fog | 19° /15° | 0 mm | 2 | |
| Sept. 27 | Fog | 20° /7° | 0 mm | 1 | |
| Sept. 28 | Mist | 21° /14° | 2.4 mm | 3 | |
| Sept. 29 | Fog | 23° /13° | 0 mm | 4 | |
| Sept. 30 | Mist | 26° /12° | 0 mm | 5 | |
| Next | |||||
Important Notice
Our weather forecast for Johnstown 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 Johnstown forecast closer to your planned date for the most up-to-date weather information.
Change Month
Johnstown in September - FAQ
What are the expected maximum and minimum temperatures in Johnstown during September?
Enjoy moderate daytime temperatures of up to 21° and cooler nights around 13°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Johnstown during September?
Significant rainfall exceeding 217.4 mm is expected in Johnstown during September, occurring over more than 7 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Johnstown during September?
The average wind speed in Johnstown during September is 11 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Johnstown
Explore the daily rainfall trends and prepare for Johnstowns September weather 💧
Typically, Johnstown has 7 rainy days in September with a total of 217.4 mm of rainfall.
UV exposure in Johnstown during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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