Weather on September 25
Allentown, PA
55 Years of Data
Avg High
70°F
Avg Low
50°F
Warmest
2017
78°F avg
Coldest
1997
50°F avg
About This Date
September 25th in Allentown, PA typically brings pleasant fall weather, with average highs around 70°F and lows near 50°F. Over 55 years of records, the warmest September 25th was in 2017 (78°F average), while the coldest was 1997 (50°F) — a 28°F range across recorded history. Rain or other precipitation has occurred on about 36% of September 25th dates historically, with the wettest September 25th recording 3.76" of rain. The last decade has been 4.4°F warmer on this date compared to 20-30 years ago.
The last decade has been 4.4°F warmer on this date compared to 20-30 years ago.
Planning for September 25th in Allentown, PA? Great weather for outdoor activities. Consider bringing rain gear or an umbrella.
Warming Trend
1.2°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 78° | 63° | 70° | 0.76" | — |
| 2024 | 65° | 58° | 61° | 0.46" | — |
| 2023 | 62° | 55° | 59° | 0.3" | — |
| 2022 | 65° | 51° | 58° | 2.49" | — |
| 2021 | 75° | 47° | 61° | — | — |
| 2020 | 78° | 49° | 63° | — | — |
| 2019 | 81° | 50° | 65° | — | — |
| 2018 | 65° | 57° | 61° | 3.53" | — |
| 2017warmest | 92° | 64° | 78° | — | — |
| 2016 | 73° | 43° | 58° | — | — |
| 2015 | 76° | 56° | 66° | — | — |
| 2014 | 64° | 50° | 57° | 0.66" | — |
| 2013 | 74° | 41° | 57° | — | — |
| 2012 | 72° | 39° | 55° | — | — |
| 2011 | 79° | 62° | 70° | — | — |
| 2010 | 85° | 61° | 73° | — | — |
| 2009 | 71° | 47° | 59° | — | — |
| 2008 | 66° | 49° | 57° | 0.25" | — |
| 2007 | 89° | 48° | 69° | — | — |
| 2006 | 70° | 51° | 60° | — | — |
| 2005 | 73° | 63° | 68° | — | — |
| 2004 | 76° | 54° | 65° | — | — |
| 2003 | 78° | 51° | 65° | 1.17" | — |
| 2002 | 73° | 47° | 60° | — | — |
| 2001 | 67° | 45° | 56° | 0.61" | — |
| 2000 | 60° | 45° | 52° | 0.38" | — |
| 1999 | 74° | 51° | 62° | — | — |
| 1998 | 64° | 49° | 56° | 0.51" | — |
| 1997coldest | 65° | 35° | 50° | — | — |
| 1996 | 67° | 46° | 56° | — | — |
| 1995 | 63° | 54° | 58° | 2.11" | — |
| 1994 | 74° | 63° | 68° | — | — |
| 1993 | 71° | 44° | 58° | 1.24" | — |
| 1992 | 60° | 43° | 51° | 2.03" | — |
| 1991 | 65° | 55° | 60° | 3.76" | — |
| 1990 | 69° | 38° | 53° | — | — |
| 1989 | 65° | 37° | 51° | 0.18" | — |
| 1988 | 64° | 53° | 59° | 0.1" | — |
| 1987 | 63° | 43° | 53° | — | — |
| 1986 | 74° | 60° | 67° | — | — |
| 1985 | 73° | 48° | 61° | — | — |
| 1984 | 85° | 65° | 75° | — | — |
| 1983 | 68° | 38° | 53° | — | — |
| 1982 | 73° | 52° | 62° | — | — |
| 1981 | 74° | 46° | 60° | — | — |
| 1980 | 62° | 59° | 61° | 0.3" | — |
| 1979 | 68° | 49° | 58° | — | — |
| 1978 | 72° | 50° | 61° | — | — |
| 1977 | 57° | 53° | 55° | 2.79" | — |
| 1976 | 69° | 43° | 56° | — | — |
| 1975 | 60° | 55° | 58° | 0.81" | — |
| 1974 | 64° | 38° | 51° | — | — |
| 1973 | 62° | 54° | 58° | — | — |
| 1972 | 77° | 53° | 65° | — | — |
| 1971 | 66° | 39° | 53° | — | — |
55 years of data from ALLENTOWN LEHIGH VLY INTL AP