Weather on September 18
Allentown, PA
55 Years of Data
Avg High
75°F
Avg Low
54°F
Warmest
2018
76°F avg
Coldest
1990
50°F avg
About This Date
September 18th in Allentown, PA typically brings pleasant fall weather, with average highs around 75°F and lows near 54°F. Over 55 years of records, the warmest September 18th was in 2018 (76°F average), while the coldest was 1990 (50°F) — a 26°F range across recorded history. Rain or other precipitation has occurred on about 35% of September 18th dates historically, with the wettest September 18th recording 11.66" of rain. The last decade has been 5.9°F warmer on this date compared to 20-30 years ago.
The last decade has been 5.9°F warmer on this date compared to 20-30 years ago.
Planning for September 18th in Allentown, PA? Great weather for outdoor activities. Consider bringing rain gear or an umbrella.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 86° | 59° | 73° | — | — |
| 2024 | 73° | 60° | 67° | — | — |
| 2023 | 72° | 54° | 63° | 0.3" | — |
| 2022 | 82° | 55° | 69° | — | — |
| 2021 | 84° | 65° | 74° | — | — |
| 2020 | 72° | 48° | 60° | — | — |
| 2019 | 75° | 50° | 63° | — | — |
| 2018warmest | 85° | 67° | 76° | 1.7" | — |
| 2017 | 76° | 64° | 70° | — | — |
| 2016 | 83° | 68° | 75° | — | — |
| 2015 | 87° | 52° | 69° | — | — |
| 2014 | 76° | 45° | 60° | — | — |
| 2013 | 71° | 40° | 55° | — | — |
| 2012 | 75° | 65° | 70° | 4.83" | — |
| 2011 | 69° | 42° | 56° | — | — |
| 2010 | 74° | 46° | 60° | — | — |
| 2009 | 73° | 52° | 62° | — | — |
| 2008 | 75° | 49° | 62° | — | — |
| 2007 | 73° | 42° | 58° | — | — |
| 2006 | 83° | 55° | 69° | — | — |
| 2005 | 82° | 58° | 70° | — | — |
| 2004 | 74° | 51° | 62° | 11.66" | — |
| 2003 | 71° | 56° | 63° | 0.89" | — |
| 2002 | 76° | 50° | 63° | — | — |
| 2001 | 78° | 47° | 62° | — | — |
| 2000 | 74° | 48° | 61° | — | — |
| 1999 | 73° | 45° | 59° | — | — |
| 1998 | 77° | 50° | 64° | — | — |
| 1997 | 79° | 54° | 66° | 0.03" | — |
| 1996 | 67° | 56° | 61° | 0.03" | — |
| 1995 | 73° | 51° | 62° | — | — |
| 1994 | 72° | 53° | 62° | 0.23" | — |
| 1993 | 69° | 57° | 63° | 0.3" | — |
| 1992 | 84° | 61° | 72° | — | — |
| 1991 | 84° | 67° | 75° | 0.86" | — |
| 1990coldest | 65° | 36° | 50° | — | — |
| 1989 | 71° | 56° | 63° | 0.03" | — |
| 1988 | 73° | 61° | 67° | — | — |
| 1987 | 72° | 55° | 63° | 1.3" | — |
| 1986 | 68° | 38° | 53° | 0.23" | — |
| 1985 | 76° | 48° | 62° | — | — |
| 1984 | 71° | 40° | 55° | — | — |
| 1983 | 80° | 51° | 66° | — | — |
| 1982 | 73° | 47° | 60° | — | — |
| 1981 | 69° | 55° | 62° | 2.51" | — |
| 1980 | 77° | 55° | 66° | 0.2" | — |
| 1979 | 76° | 51° | 63° | — | — |
| 1978 | 79° | 65° | 72° | 1.35" | — |
| 1977 | 84° | 64° | 74° | — | — |
| 1976 | 72° | 58° | 65° | — | — |
| 1975 | 66° | 59° | 63° | 0.36" | — |
| 1974 | 75° | 59° | 67° | — | — |
| 1973 | 73° | 55° | 64° | 1.55" | — |
| 1972 | 78° | 65° | 71° | 1.22" | — |
| 1971 | 76° | 65° | 70° | — | — |
55 years of data from ALLENTOWN LEHIGH VLY INTL AP