Weather on September 18
Allentown, PA
55 Years of Data
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° | — | — |
Allentown, PA Temperature Range by Month
Average monthly highs and lows. The shaded band shows the typical daily temperature range.
Allentown, PA Monthly Precipitation
Average rainfall and snowfall per month, in inches.
Allentown, PA Daily Temperature Calendar
Average daily high temperature for every day of the year. Each cell is the climatological mean for that calendar day across 55 years of NOAA data.
Best Time to Visit Allentown, PA
Allentown, PA has no months that meet our "pleasant" threshold — every season has tradeoffs.