Weather on April 21
Joliet, IL
55 Years of Data
Avg High
63°F
Avg Low
42°F
Warmest
1985
72°F avg
Coldest
1978
37°F avg
About This Date
April 21st in Joliet, IL typically brings mild spring weather, with average highs around 63°F and lows near 42°F. Over 54 years of records, the warmest April 21st was in 1985 (72°F average), while the coldest was 1978 (37°F) — a 35°F range across recorded history. Rain or other precipitation has occurred on about 54% of April 21st dates historically, with the wettest April 21st recording 3.35" of rain. The last decade has been 1.7°F cooler on this date compared to 20-30 years ago.
The last decade has been 1.7°F cooler on this date compared to 20-30 years ago.
Planning for April 21st in Joliet, IL? Great weather for outdoor activities. Consider bringing rain gear or an umbrella.
Cooling Trend
0.8°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 64° | 50° | 57° | 0.99" | — |
| 2024 | 46° | 30° | 38° | — | — |
| 2023 | 79° | 43° | 61° | 0.76" | — |
| 2022 | 51° | 40° | 45° | 1.02" | — |
| 2021 | — | 31° | — | 0.64" | — |
| 2020 | 63° | 32° | 47° | — | — |
| 2019 | 65° | 40° | 52° | — | — |
| 2018 | 62° | 30° | 46° | — | — |
| 2017 | 74° | 44° | 59° | 0.05" | — |
| 2016 | 70° | 51° | 60° | 0.97" | — |
| 2015 | 50° | 40° | 45° | — | — |
| 2014 | 77° | 43° | 60° | — | — |
| 2013 | 46° | 31° | 38° | — | — |
| 2012 | 61° | 35° | 48° | 0.03" | — |
| 2011 | 43° | 32° | 37° | — | — |
| 2010 | 66° | 41° | 54° | — | — |
| 2009 | 55° | 37° | 46° | 0.13" | — |
| 2008 | 75° | 49° | 62° | — | — |
| 2007 | 70° | 41° | 55° | — | — |
| 2006 | 74° | 48° | 61° | — | — |
| 2005 | 80° | 47° | 63° | 0.08" | — |
| 2004 | 65° | 47° | 56° | 1.78" | — |
| 2003 | 68° | 49° | 58° | 0.23" | — |
| 2002 | 51° | 42° | 47° | 0.64" | — |
| 2001 | 79° | 55° | 67° | 0.38" | — |
| 2000 | 49° | 39° | 44° | 3.35" | — |
| 1999 | 57° | 35° | 46° | 0.15" | — |
| 1998 | 64° | 44° | 54° | 1.98" | — |
| 1997 | 61° | 40° | 50° | — | — |
| 1996 | 58° | 41° | 49° | — | — |
| 1995 | 50° | 40° | 45° | 0.38" | — |
| 1994 | 65° | 41° | 53° | — | — |
| 1993 | 41° | 32° | 37° | 0.03" | — |
| 1992 | 69° | 45° | 57° | 0.03" | — |
| 1991 | 48° | 41° | 45° | — | — |
| 1990 | 61° | 51° | 56° | 0.94" | — |
| 1989 | 70° | 41° | 55° | 0.08" | — |
| 1988 | 55° | 34° | 44° | — | — |
| 1987 | 87° | 42° | 65° | — | — |
| 1986 | 59° | 39° | 49° | 0.05" | — |
| 1985warmest | 85° | 60° | 72° | — | — |
| 1984 | 59° | 31° | 45° | — | — |
| 1983 | 55° | 32° | 44° | — | — |
| 1982 | 55° | 29° | 42° | — | — |
| 1981 | 46° | 34° | 40° | — | — |
| 1980 | 78° | 41° | 60° | — | — |
| 1979 | 59° | 40° | 49° | 0.13" | — |
| 1978coldest | 43° | 31° | 37° | 0.33" | — |
| 1977 | 78° | 63° | 70° | 1.27" | — |
| 1976 | 66° | 49° | 57° | 0.3" | — |
| 1974 | 80° | 60° | 70° | — | — |
| 1973 | 73° | 60° | 67° | 3.3" | — |
| 1972 | 51° | 39° | 45° | 0.56" | — |
| 1971 | 78° | 39° | 59° | 0.3" | — |
54 years of data from JOLIET