September weather in Johnstown, PA
The average temperature in Johnstown in September is 61.6°F (52.7°F–70.5°F). Average precipitation: 3.99 inches.
September is a fall month in Johnstown, and is warmer than the annual average of 48.9°F. Daily temperatures swing about 17.8°F between overnight low and afternoon high. Expect about 12 days with precipitation. Daylight averages about 12h 15m. For travel, September is one of the best months of the year to visit.
Avg High
70.5°F
Avg Low
52.7°F
Precipitation
3.99 in
Daylight
12h 15m
September records in Johnstown
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 84.9°F (2015) | 45.0°F (2009) | 3.29 in (2021) |
| September 2 | 86.0°F (2010) | 45.0°F (2001) | 1.39 in (2006) |
| September 3 | 86.0°F (2011) | 46.0°F (2009) | 0.60 in (2020) |
| September 4 | 88.0°F (2018) | 50.0°F (2006) | 1.90 in (2011) |
| September 5 | 86.0°F (2018) | 43.0°F (2000) | 1.14 in (2022) |
| September 6 | 86.0°F (2007) | 41.0°F (2000) | 1.94 in (2011) |
| September 7 | 87.1°F (2015) | 46.0°F (2000) | 0.82 in (2011) |
| September 8 | 88.0°F (2015) | 42.1°F (2025) | 2.23 in (2004) |
| September 9 | 88.0°F (2002) | 42.1°F (2017) | 2.73 in (2018) |
| September 10 | 87.1°F (2002) | 42.1°F (2017) | 1.59 in (2000) |
| September 11 | 84.9°F (2019) | 43.0°F (2012) | 1.01 in (2013) |
| September 12 | 82.9°F (2005) | 48.0°F (2002) | 2.94 in (2008) |
| September 13 | 84.0°F (2005) | 44.1°F (2013) | 0.62 in (2006) |
| September 14 | 82.0°F (2005) | 41.0°F (2013) | 0.29 in (2001) |
| September 15 | 82.9°F (2005) | 37.9°F (2001) | 0.44 in (2011) |
| September 16 | 82.9°F (2005) | 37.0°F (2007) | 0.95 in (2010) |
| September 17 | 81.0°F (2015) | 39.0°F (2013) | 2.14 in (2004) |
| September 18 | 82.0°F (2015) | 43.0°F (2010) | 1.23 in (2012) |
| September 19 | 84.0°F (2015) | 36.0°F (2020) | 1.20 in (2003) |
| September 20 | 81.0°F (2002) | 37.0°F (2020) | 0.52 in (2001) |
| September 21 | 84.0°F (2018) | 39.0°F (2006) | 1.04 in (2024) |
| September 22 | 82.9°F (2005) | 37.0°F (2020) | 1.46 in (2021) |
| September 23 | 82.9°F (2017) | 37.0°F (2014) | 0.78 in (2024) |
| September 24 | 84.0°F (2017) | 34.0°F (2013) | 1.43 in (2001) |
| September 25 | 84.9°F (2017) | 39.9°F (2001) | 1.59 in (2025) |
| September 26 | 84.0°F (2017) | 39.9°F (2000) | 1.09 in (2009) |
| September 27 | 82.9°F (2017) | 39.0°F (2000) | 1.40 in (2012) |
| September 28 | 81.0°F (2019) | 39.9°F (2000) | 1.27 in (2021) |
| September 29 | 73.9°F (2025) | 32.0°F (2000) | 2.11 in (2015) |
| September 30 | 75.9°F (2025) | 37.0°F (2005) | 2.73 in (2010) |