Weather on September 30
Joliet, IL
55 Years of Data
Avg High
72°F
Avg Low
49°F
Warmest
1971
79°F avg
Coldest
1984
44°F avg
About This Date
September 30th in Joliet, IL typically brings pleasant fall weather, with average highs around 72°F and lows near 49°F. Over 54 years of records, the warmest September 30th was in 1971 (79°F average), while the coldest was 1984 (44°F) — a 35°F range across recorded history. Rain or other precipitation has occurred on about 22% of September 30th dates historically, with the wettest September 30th recording 2.49" of rain. The last decade has been 1.9°F warmer on this date compared to 20-30 years ago.
The last decade has been 1.9°F warmer on this date compared to 20-30 years ago.
Planning for September 30th in Joliet, IL? Great weather for outdoor activities.
Cooling Trend
0.5°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 86° | 59° | 72° | — | — |
| 2024 | 74° | 63° | 68° | — | — |
| 2023 | 77° | 56° | 66° | — | — |
| 2022 | 65° | 41° | 53° | — | — |
| 2021 | 85° | — | — | — | — |
| 2020 | 59° | 43° | 51° | — | — |
| 2019 | 70° | 62° | 66° | 0.41" | — |
| 2018 | 58° | 40° | 49° | — | — |
| 2017 | 71° | 49° | 60° | — | — |
| 2016 | 67° | 60° | 63° | 0.79" | — |
| 2015 | 65° | 52° | 58° | — | — |
| 2014 | 81° | 52° | 66° | — | — |
| 2013 | 68° | 47° | 57° | — | — |
| 2012 | 78° | 46° | 62° | — | — |
| 2011 | 67° | 49° | 58° | 0.18" | — |
| 2010 | 77° | 48° | 63° | — | — |
| 2009 | 61° | 44° | 52° | — | — |
| 2008 | 63° | 51° | 57° | 0.18" | — |
| 2007 | 74° | 51° | 62° | — | — |
| 2006 | 61° | 42° | 51° | 0.05" | — |
| 2005 | 62° | 43° | 52° | — | — |
| 2004 | 67° | 44° | 55° | — | — |
| 2003 | 58° | 40° | 49° | — | — |
| 2002 | 86° | 62° | 74° | — | — |
| 2001 | 67° | 48° | 57° | — | — |
| 2000 | 75° | 46° | 61° | — | — |
| 1999 | 65° | 41° | 53° | — | — |
| 1998 | 76° | 56° | 66° | 0.2" | — |
| 1997 | 77° | 54° | 65° | — | — |
| 1996 | 67° | 49° | 58° | — | — |
| 1995 | 80° | 54° | 67° | — | — |
| 1994 | 71° | 43° | 57° | — | — |
| 1993 | 53° | 35° | 44° | 0.03" | — |
| 1992 | 64° | 38° | 51° | — | — |
| 1991 | 83° | 54° | 68° | — | — |
| 1990 | 69° | 49° | 59° | 0.03" | — |
| 1989 | 76° | 47° | 61° | — | — |
| 1988 | 81° | 57° | 69° | — | — |
| 1987 | 67° | 49° | 58° | — | — |
| 1986 | 79° | 66° | 72° | 2.49" | — |
| 1985 | 76° | 44° | 60° | 0.74" | — |
| 1984coldest | 55° | 34° | 44° | — | — |
| 1983 | 81° | 51° | 66° | — | — |
| 1982 | 84° | 55° | 70° | — | — |
| 1981 | 65° | 47° | 56° | 0.3" | — |
| 1980 | 79° | 49° | 64° | — | — |
| 1979 | 84° | 55° | 70° | — | — |
| 1978 | 75° | 42° | 59° | 0.71" | — |
| 1977 | 74° | 48° | 61° | — | — |
| 1976 | 69° | 45° | 57° | — | — |
| 1975 | 64° | 50° | 57° | — | — |
| 1974 | 65° | 43° | 54° | — | — |
| 1973 | 70° | 56° | 63° | — | — |
| 1971warmest | 93° | 64° | 79° | — | — |
54 years of data from JOLIET