Weather on August 21
Allentown, PA
55 Years of Data
Avg High
81°F
Avg Low
60°F
Warmest
2019
81°F avg
Coldest
2007
58°F avg
About This Date
August 21st in Allentown, PA typically brings warm summer weather, with average highs around 81°F and lows near 60°F. Over 55 years of records, the warmest August 21st was in 2019 (81°F average), while the coldest was 2007 (58°F) — a 23°F range across recorded history. Rain or other precipitation has occurred on about 33% of August 21st dates historically, with the wettest August 21st recording 6.17" of rain. The last decade has been 3.6°F warmer on this date compared to 20-30 years ago.
The last decade has been 3.6°F warmer on this date compared to 20-30 years ago.
Planning for August 21st in Allentown, PA? Stay hydrated and seek shade during peak afternoon hours. Consider bringing rain gear or an umbrella.
Warming Trend
0.8°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 74° | 58° | 66° | 0.03" | — |
| 2024 | 72° | 49° | 60° | — | — |
| 2023 | 86° | 63° | 74° | — | — |
| 2022 | 89° | 63° | 76° | 0.03" | — |
| 2021 | 84° | 68° | 76° | 0.05" | — |
| 2020 | 85° | 58° | 71° | — | — |
| 2019warmest | 90° | 73° | 81° | — | — |
| 2018 | 77° | 69° | 73° | 6.17" | — |
| 2017 | 86° | 61° | 73° | — | — |
| 2016 | 89° | 66° | 78° | 1.85" | — |
| 2015 | 84° | 63° | 73° | — | — |
| 2014 | 83° | 67° | 75° | 1.24" | — |
| 2013 | 86° | 58° | 72° | — | — |
| 2012 | 82° | 57° | 70° | — | — |
| 2011 | 85° | 66° | 75° | 2.44" | — |
| 2010 | 87° | 57° | 72° | — | — |
| 2009 | 88° | 70° | 79° | 1.96" | — |
| 2008 | 83° | 50° | 66° | — | — |
| 2007coldest | 61° | 56° | 58° | 3.48" | — |
| 2006 | 84° | 64° | 74° | — | — |
| 2005 | 91° | 64° | 78° | — | — |
| 2004 | 78° | 56° | 67° | 2.79" | — |
| 2003 | 89° | 65° | 77° | — | — |
| 2002 | 87° | 59° | 73° | — | — |
| 2001 | 80° | 59° | 70° | — | — |
| 2000 | 74° | 45° | 59° | — | — |
| 1999 | 65° | 59° | 62° | — | — |
| 1998 | 85° | 52° | 68° | 0.05" | — |
| 1997 | 76° | 59° | 67° | 0.05" | — |
| 1996 | 80° | 63° | 71° | — | — |
| 1995 | 93° | 58° | 75° | — | — |
| 1994 | 82° | 68° | 75° | 3" | — |
| 1993 | 79° | 58° | 68° | — | — |
| 1992 | 78° | 50° | 64° | — | — |
| 1991 | 80° | 64° | 72° | — | — |
| 1990 | 62° | 56° | 59° | 0.64" | — |
| 1989 | 86° | 67° | 76° | — | — |
| 1988 | 81° | 56° | 68° | — | — |
| 1987 | 84° | 55° | 70° | — | — |
| 1986 | 68° | 59° | 64° | 2.18" | — |
| 1985 | 75° | 64° | 70° | 0.03" | — |
| 1984 | 78° | 50° | 64° | — | — |
| 1983 | 86° | 65° | 75° | — | — |
| 1982 | 73° | 53° | 63° | — | — |
| 1981 | 82° | 50° | 66° | — | — |
| 1980 | 79° | 65° | 72° | — | — |
| 1979 | 78° | 65° | 71° | — | — |
| 1978 | 80° | 56° | 68° | — | — |
| 1977 | 74° | 47° | 60° | 0.74" | — |
| 1976 | 89° | 59° | 74° | — | — |
| 1975 | 78° | 57° | 68° | — | — |
| 1974 | 83° | 64° | 73° | — | — |
| 1973 | 75° | 60° | 68° | — | — |
| 1972 | 84° | 52° | 68° | — | — |
| 1971 | 87° | 67° | 77° | 0.48" | — |
55 years of data from ALLENTOWN LEHIGH VLY INTL AP