Weather on September 23
Allentown, PA
55 Years of Data
Avg High
72°F
Avg Low
52°F
Warmest
2019
76°F avg
Coldest
1974
45°F avg
About This Date
September 23rd in Allentown, PA typically brings pleasant fall weather, with average highs around 72°F and lows near 52°F. Over 55 years of records, the warmest September 23rd was in 2019 (76°F average), while the coldest was 1974 (45°F) — a 31°F range across recorded history. Rain or other precipitation has occurred on about 40% of September 23rd dates historically, with the wettest September 23rd recording 4.93" of rain. The last decade has been 4.7°F warmer on this date compared to 20-30 years ago.
The last decade has been 4.7°F warmer on this date compared to 20-30 years ago.
Planning for September 23rd in Allentown, PA? Great weather for outdoor activities. Consider bringing rain gear or an umbrella.
Warming Trend
1.3°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 83° | 61° | 72° | — | — |
| 2024 | 65° | 58° | 61° | 0.69" | — |
| 2023 | 58° | 54° | 56° | 1.19" | — |
| 2022 | 62° | 45° | 53° | 0.03" | — |
| 2021 | 75° | 56° | 65° | 4.47" | — |
| 2020 | 81° | 49° | 65° | — | — |
| 2019warmest | 90° | 63° | 76° | — | — |
| 2018 | 66° | 57° | 62° | 0.05" | — |
| 2017 | 90° | 59° | 74° | — | — |
| 2016 | 90° | 51° | 70° | — | — |
| 2015 | 81° | 47° | 64° | — | — |
| 2014 | 73° | 40° | 56° | — | — |
| 2013 | 64° | 43° | 53° | — | — |
| 2012 | 66° | 47° | 56° | — | — |
| 2011 | 73° | 65° | 69° | 4.14" | — |
| 2010 | 82° | 58° | 70° | — | — |
| 2009 | 80° | 62° | 71° | — | — |
| 2008 | 72° | 49° | 60° | — | — |
| 2007 | 80° | 54° | 67° | — | — |
| 2006 | 75° | 60° | 68° | 0.41" | — |
| 2005 | 85° | 62° | 73° | — | — |
| 2004 | 83° | 57° | 70° | — | — |
| 2003 | 74° | 51° | 62° | 4.5" | — |
| 2002 | 71° | 49° | 60° | 0.08" | — |
| 2001 | 79° | 57° | 68° | — | — |
| 2000 | 62° | 47° | 54° | 0.15" | — |
| 1999 | 71° | 42° | 57° | — | — |
| 1998 | 64° | 40° | 52° | — | — |
| 1997 | 63° | 47° | 55° | — | — |
| 1996 | 67° | 45° | 56° | — | — |
| 1995 | 60° | 46° | 53° | — | — |
| 1994 | 68° | 57° | 63° | 0.3" | — |
| 1993 | 70° | 47° | 58° | 0.38" | — |
| 1992 | 64° | 45° | 54° | — | — |
| 1991 | 65° | 51° | 58° | 0.18" | — |
| 1990 | 62° | 47° | 54° | — | — |
| 1989 | 78° | 44° | 61° | 0.76" | — |
| 1988 | 81° | 59° | 70° | 0.08" | — |
| 1987 | 68° | 48° | 58° | — | — |
| 1986 | 83° | 64° | 73° | 1.42" | — |
| 1985 | 70° | 65° | 67° | 0.03" | — |
| 1984 | 83° | 53° | 68° | — | — |
| 1983 | 62° | 39° | 51° | — | — |
| 1982 | 63° | 53° | 58° | 0.15" | — |
| 1981 | 58° | 48° | 53° | — | — |
| 1980 | 82° | 59° | 71° | — | — |
| 1979 | 66° | 50° | 58° | — | — |
| 1978 | 69° | 49° | 59° | — | — |
| 1977 | 64° | 57° | 61° | 0.66" | — |
| 1976 | 74° | 38° | 56° | — | — |
| 1975 | 61° | 56° | 58° | 4.93" | — |
| 1974coldest | 55° | 36° | 45° | — | — |
| 1973 | 80° | 60° | 70° | 0.91" | — |
| 1972 | 66° | 40° | 53° | — | — |
| 1971 | 66° | 56° | 61° | 0.18" | — |
55 years of data from ALLENTOWN LEHIGH VLY INTL AP