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Allentown, PA Weather on April 20
April 20th in Allentown, PA typically brings mild spring weather, with average highs around 66°F and lows near 43°F. Over 55 years of records, the warmest April 20th was in 1976 (73°F average), while the coldest was 1983 (39°F) — a 34°F range across recorded history. Rain or other precipitation has occurred on about 29% of April 20th dates historically, with the wettest April 20th recording 3.78" of rain. Temperatures on this date have remained relatively stable over the past several decades.
What to Expect on April 20
Planning for April 20th in Allentown, PA? Great weather for outdoor activities.
April 20 Weather Records for Allentown
- •The all-time record high for April 20th in Allentown, PA is 88°F, set in 1976.
- •The coldest April 20th on record dropped to 31°F in 1974.
- •A freeze (32°F or below) has occurred on April 20th in 4 of the last 55 years.
Frequently Asked Questions
What was the warmest April 20 ever in Allentown?
The warmest April 20 in Allentown, PA reached 88°F in 1976. That is 22°F above the long-term average high of 66°F.
What was the coldest April 20 ever in Allentown?
The coldest April 20 in Allentown, PA dropped to 31°F in 1974. That is 12°F below the long-term average low of 43°F.
What is the average temperature on April 20 in Allentown?
On April 20, Allentown averages a high of 66°F and a low of 43°F based on 55 years of NOAA weather observations from ALLENTOWN LEHIGH VLY INTL AP.
How many years of weather data are available for April 20 in Allentown?
We have 55 years of weather records for April 20 in Allentown, PA, sourced from NOAA's Global Historical Climatology Network. Records include daily high and low temperatures, precipitation, and snowfall data going back to 2025.
April 20 Weather History in Allentown
| Year | High | Low | Precip | Snow |
|---|---|---|---|---|
| 2025 | 71°F | 47°F | 0" | -- |
| 2024 | 67°F | 39°F | 0.05" | -- |
| 2023 | 73°F | 42°F | 0" | -- |
| 2022 | 58°F | 37°F | 0" | -- |
| 2021 | 74°F | 35°F | 0" | -- |
| 2020 | 62°F | 40°F | 0" | -- |
| 2019 | 74°F | 58°F | 3.78" | -- |
| 2018 | 52°F | 36°F | 0" | -- |
| 2017 | 75°F | 52°F | 0.56" | -- |
| 2016 | 72°F | 41°F | 0" | -- |
| 2015 | 62°F | 47°F | 1.85" | -- |
| 2014 | 62°F | 38°F | 0" | -- |
| 2013 | 56°F | 38°F | 0.08" | -- |
| 2012 | 75°F | 42°F | 0" | -- |
| 2011 | 68°F | 45°F | 0" | -- |
| 2010 | 68°F | 35°F | 0" | -- |
| 2009 | 47°F | 42°F | 1.27" | -- |
| 2008 | 67°F | 53°F | 0" | -- |
| 2007 | 71°F | 35°F | 0" | -- |
| 2006 | 83°F | 50°F | 0" | -- |
| 2005 | 84°F | 57°F | 0" | -- |
| 2004 | 72°F | 51°F | 0" | -- |
| 2003 | 69°F | 34°F | 0" | -- |
| 2002 | 68°F | 45°F | 0.03" | -- |
| 2001 | 61°F | 32°F | 0.03" | -- |
| 2000 | 67°F | 52°F | 0" | -- |
| 1999 | 51°F | 32°F | 1.14" | -- |
| 1998 | 59°F | 43°F | 0.05" | -- |
| 1997 | 54°F | 38°F | 0.03" | -- |
| 1996 | 74°F | 48°F | 0" | -- |
| 1995 | 66°F | 49°F | 0" | -- |
| 1994 | 63°F | 44°F | 0" | -- |
| 1993 | 75°F | 56°F | 0" | -- |
| 1992 | 57°F | 43°F | 0" | -- |
| 1991 | 48°F | 42°F | 0" | -- |
| 1990 | 66°F | 45°F | 0.08" | -- |
| 1989 | 63°F | 35°F | 0" | -- |
| 1988 | 57°F | 34°F | 0" | -- |
| 1987 | 76°F | 48°F | 0" | -- |
| 1986 | 70°F | 39°F | 0" | -- |
| 1985 | 75°F | 56°F | 0.23" | -- |
| 1984 | 61°F | 39°F | 0" | -- |
| 1983 | 46°F | 32°F | 0" | -- |
| 1982 | 68°F | 39°F | 0" | -- |
| 1981 | 53°F | 33°F | 0" | -- |
| 1980 | 74°F | 40°F | 0.08" | -- |
| 1979 | 65°F | 33°F | 0" | -- |
| 1978 | 60°F | 46°F | 1.6" | -- |
| 1977 | 69°F | 49°F | 0" | -- |
| 1976 | 88°F | 58°F | 0" | -- |
| 1975 | 56°F | 43°F | 0" | -- |
| 1974 | 62°F | 31°F | 0" | -- |
| 1973 | 68°F | 45°F | 0" | -- |
| 1972 | 72°F | 39°F | 0.97" | -- |
| 1971 | 70°F | 44°F | 0" | -- |
Based on 55 years of data from NOAA station: ALLENTOWN LEHIGH VLY INTL AP
Monthly Climate Averages
Historical temperature and precipitation averages for Allentown, PA, based on 55+ years of weather data.
Temperatures in Fahrenheit. Precipitation and snowfall in inches.