Basile Morin / CC BY-SA 4.0
Allentown, PA Weather on September 13
September 13th in Allentown, PA typically brings pleasant fall weather, with average highs around 78°F and lows near 56°F. Over 55 years of records, the warmest September 13th was in 1974 (75°F average), while the coldest was 1985 (53°F) — a 22°F range across recorded history. Rain or other precipitation has occurred on about 33% of September 13th dates historically, with the wettest September 13th recording 1.7" of rain. The last decade has been 1.7°F warmer on this date compared to 20-30 years ago.
What to Expect on September 13
Planning for September 13th in Allentown, PA? Great weather for outdoor activities. Consider bringing rain gear or an umbrella.
September 13 Weather Records for Allentown
- •The all-time record high for September 13th in Allentown, PA is 92°F, set in 2005.
- •The coldest September 13th on record dropped to 43°F in 2002.
- •Temperatures have reached 90°F or higher on September 13th in 1 of the last 55 years.
- •Last year (1971), September 13th was 5°F cooler than the long-term average.
Frequently Asked Questions
What was the warmest September 13 ever in Allentown?
The warmest September 13 in Allentown, PA reached 92°F in 2005. That is 14°F above the long-term average high of 78°F.
What was the coldest September 13 ever in Allentown?
The coldest September 13 in Allentown, PA dropped to 43°F in 2002. That is 13°F below the long-term average low of 56°F.
What is the average temperature on September 13 in Allentown?
On September 13, Allentown averages a high of 78°F and a low of 56°F based on 55 years of NOAA weather observations from ALLENTOWN LEHIGH VLY INTL AP.
How many years of weather data are available for September 13 in Allentown?
We have 55 years of weather records for September 13 in Allentown, PA, sourced from NOAA's Global Historical Climatology Network. Records include daily high and low temperatures, precipitation, and snowfall data going back to 2025.
September 13 Weather History in Allentown
| Year | High | Low | Precip | Snow |
|---|---|---|---|---|
| 2025 | 82°F | 56°F | 0" | -- |
| 2024 | 83°F | 51°F | 0" | -- |
| 2023 | 79°F | 59°F | 0.35" | -- |
| 2022 | 79°F | 58°F | 0.09" | -- |
| 2021 | 84°F | 63°F | 0.02" | -- |
| 2020 | 79°F | 54°F | 0" | -- |
| 2019 | 69°F | 62°F | 0" | -- |
| 2018 | 79°F | 72°F | 0" | -- |
| 2017 | 74°F | 55°F | 0.16" | -- |
| 2016 | 86°F | 54°F | 0" | -- |
| 2015 | 69°F | 50°F | 0" | -- |
| 2014 | 62°F | 52°F | 0.45" | -- |
| 2013 | 74°F | 55°F | 0" | -- |
| 2012 | 81°F | 50°F | 0" | -- |
| 2011 | 83°F | 58°F | 0" | -- |
| 2010 | 79°F | 54°F | 0" | -- |
| 2009 | 78°F | 61°F | 0" | -- |
| 2008 | 83°F | 63°F | 0.01" | -- |
| 2007 | 77°F | 47°F | 0" | -- |
| 2006 | 65°F | 52°F | 0.05" | -- |
| 2005 | 92°F | 57°F | 0" | -- |
| 2004 | 85°F | 56°F | 0" | -- |
| 2003 | 72°F | 62°F | 0.68" | -- |
| 2002 | 83°F | 43°F | 0" | -- |
| 2001 | 85°F | 49°F | 0.64" | -- |
| 2000 | 76°F | 54°F | 0.61" | -- |
| 1999 | 78°F | 54°F | 0" | -- |
| 1998 | 82°F | 61°F | 0" | -- |
| 1997 | 75°F | 54°F | 0" | -- |
| 1996 | 72°F | 54°F | 0.11" | -- |
| 1995 | 77°F | 62°F | 0.18" | -- |
| 1994 | 87°F | 56°F | 0" | -- |
| 1993 | 82°F | 59°F | 0" | -- |
| 1992 | 72°F | 44°F | 0" | -- |
| 1991 | 83°F | 51°F | 0" | -- |
| 1990 | 83°F | 63°F | 0.1" | -- |
| 1989 | 82°F | 61°F | 0" | -- |
| 1988 | 82°F | 60°F | 0.89" | -- |
| 1987 | 77°F | 67°F | 0.73" | -- |
| 1986 | 75°F | 52°F | 0" | -- |
| 1985 | 64°F | 43°F | 0" | -- |
| 1984 | 80°F | 52°F | 0" | -- |
| 1983 | 67°F | 58°F | 0" | -- |
| 1982 | 83°F | 58°F | 0" | -- |
| 1981 | 86°F | 54°F | 0" | -- |
| 1980 | 87°F | 63°F | 0" | -- |
| 1979 | 78°F | 53°F | 0" | -- |
| 1978 | 70°F | 56°F | 0" | -- |
| 1977 | 76°F | 59°F | 0" | -- |
| 1976 | 89°F | 53°F | 0" | -- |
| 1975 | 64°F | 45°F | 0" | -- |
| 1974 | 84°F | 66°F | 1.54" | -- |
| 1973 | 75°F | 47°F | 0" | -- |
| 1972 | 78°F | 61°F | 0.2" | -- |
| 1971 | 73°F | 61°F | 1.7" | -- |
Based on 55 years of data from NOAA station: ALLENTOWN LEHIGH VLY INTL AP
Monthly Climate Averages
Historical temperature and precipitation averages for Allentown, PA, based on 55+ years of weather data.
Temperatures in Fahrenheit. Precipitation and snowfall in inches.