Weather on May 21
Allentown, PA
55 Years of Data
Avg High
74°F
Avg Low
51°F
Warmest
2022
77°F avg
Coldest
2002
45°F avg
About This Date
May 21st in Allentown, PA typically brings pleasant spring weather, with average highs around 74°F and lows near 51°F. Over 55 years of records, the warmest May 21st was in 2022 (77°F average), while the coldest was 2002 (45°F) — a 32°F range across recorded history. Rain or other precipitation has occurred on about 38% of May 21st dates historically, with the wettest May 21st recording 2.72" 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 May 21st in Allentown, PA? Great weather for outdoor activities. Consider bringing rain gear or an umbrella.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 56° | 48° | 52° | 1.32" | — |
| 2024 | 85° | 57° | 71° | — | — |
| 2023 | 77° | 50° | 64° | — | — |
| 2022warmest | 89° | 64° | 77° | — | — |
| 2021 | 87° | 52° | 69° | — | — |
| 2020 | 74° | 34° | 54° | — | — |
| 2019 | 73° | 54° | 63° | — | — |
| 2018 | 80° | 53° | 67° | — | — |
| 2017 | 72° | 46° | 59° | — | — |
| 2016 | 67° | 52° | 59° | 0.64" | — |
| 2015 | 61° | 46° | 53° | — | — |
| 2014 | 69° | 57° | 63° | — | — |
| 2013 | 88° | 58° | 73° | — | — |
| 2012 | 67° | 58° | 62° | 0.41" | — |
| 2011 | 80° | 51° | 66° | 0.03" | — |
| 2010 | 87° | 53° | 70° | — | — |
| 2009 | 84° | 43° | 63° | — | — |
| 2008 | 66° | 39° | 53° | — | — |
| 2007 | 70° | 48° | 59° | — | — |
| 2006 | 65° | 39° | 52° | 0.03" | — |
| 2005 | 72° | 38° | 55° | 0.03" | — |
| 2004 | 81° | 65° | 73° | — | — |
| 2003 | 60° | 55° | 58° | 0.56" | — |
| 2002coldest | 58° | 32° | 45° | 0.03" | — |
| 2001 | 57° | 50° | 54° | 2.72" | — |
| 2000 | 60° | 50° | 55° | 0.18" | — |
| 1999 | 78° | 41° | 60° | — | — |
| 1998 | 81° | 56° | 68° | — | — |
| 1997 | 61° | 38° | 49° | — | — |
| 1996 | 89° | 59° | 74° | 0.61" | — |
| 1995 | 79° | 49° | 64° | — | — |
| 1994 | 82° | 40° | 61° | — | — |
| 1993 | 68° | 39° | 54° | — | — |
| 1992 | 86° | 45° | 65° | — | — |
| 1991 | 79° | 46° | 62° | — | — |
| 1990 | 52° | 48° | 50° | 0.1" | — |
| 1989 | 81° | 57° | 69° | 0.03" | — |
| 1988 | 73° | 57° | 65° | 0.03" | — |
| 1987 | 74° | 51° | 62° | — | — |
| 1986 | 76° | 63° | 69° | 0.76" | — |
| 1985 | 82° | 58° | 70° | — | — |
| 1984 | 79° | 55° | 67° | — | — |
| 1983 | 68° | 56° | 62° | 0.1" | — |
| 1982 | 72° | 57° | 64° | 0.03" | — |
| 1981 | 77° | 43° | 60° | — | — |
| 1980 | 64° | 55° | 60° | 1.6" | — |
| 1979 | 67° | 53° | 60° | — | — |
| 1978 | 80° | 53° | 67° | — | — |
| 1977 | 86° | 61° | 73° | — | — |
| 1976 | 78° | 52° | 65° | 0.36" | — |
| 1975 | 80° | 67° | 73° | — | — |
| 1974 | 74° | 47° | 60° | — | — |
| 1973 | 58° | 49° | 53° | 0.56" | — |
| 1972 | 78° | 58° | 68° | — | — |
| 1971 | 61° | 48° | 54° | 0.79" | — |
55 years of data from ALLENTOWN LEHIGH VLY INTL AP