Weather on September 18
Joliet, IL
55 Years of Data
Avg High
76°F
Avg Low
53°F
Warmest
2018
78°F avg
Coldest
1981
49°F avg
About This Date
September 18th in Joliet, IL typically brings pleasant fall weather, with average highs around 76°F and lows near 53°F. Over 54 years of records, the warmest September 18th was in 2018 (78°F average), while the coldest was 1981 (49°F) — a 29°F range across recorded history. Rain or other precipitation has occurred on about 35% of September 18th dates historically, with the wettest September 18th recording 6.22" of rain. The last decade has been 5.2°F warmer on this date compared to 20-30 years ago.
The last decade has been 5.2°F warmer on this date compared to 20-30 years ago.
Planning for September 18th in Joliet, IL? Great weather for outdoor activities. Consider bringing rain gear or an umbrella.
Warming Trend
1.6°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 88° | 56° | 72° | — | — |
| 2024 | 85° | 57° | 71° | — | — |
| 2023 | 67° | 50° | 58° | 0.15" | — |
| 2022 | 81° | 62° | 71° | — | — |
| 2021 | 88° | 63° | 75° | — | — |
| 2020 | — | 54° | — | — | — |
| 2019 | 81° | 62° | 71° | — | — |
| 2018warmest | 90° | 66° | 78° | — | — |
| 2017 | 84° | 58° | 71° | — | — |
| 2016 | 81° | 59° | 70° | — | — |
| 2015 | 84° | 61° | 72° | 1.65" | — |
| 2014 | 72° | 45° | 58° | — | — |
| 2013 | 71° | 51° | 61° | — | — |
| 2012 | 77° | 49° | 63° | 1.52" | — |
| 2011 | 69° | 50° | 60° | 0.03" | — |
| 2010 | 76° | 51° | 63° | — | — |
| 2009 | 72° | 49° | 60° | — | — |
| 2008 | 82° | 55° | 69° | — | — |
| 2007 | 72° | 48° | 60° | — | — |
| 2006 | 84° | 60° | 72° | 1.57" | — |
| 2005 | 77° | 52° | 64° | — | — |
| 2004 | 71° | 55° | 63° | — | — |
| 2003 | 82° | 55° | 69° | — | — |
| 2002 | 80° | 54° | 67° | 0.86" | — |
| 2001 | 69° | 55° | 62° | 0.15" | — |
| 2000 | 80° | 55° | 68° | — | — |
| 1999 | 73° | 46° | 60° | — | — |
| 1998 | 80° | 64° | 72° | — | — |
| 1997 | 82° | 58° | 70° | — | — |
| 1996 | 70° | 53° | 61° | — | — |
| 1995 | 68° | 48° | 58° | — | — |
| 1994 | 76° | 55° | 65° | — | — |
| 1993 | 67° | 50° | 58° | — | — |
| 1992 | 84° | 66° | 75° | 0.15" | — |
| 1991 | 62° | 38° | 50° | 0.03" | — |
| 1990 | 62° | 47° | 54° | — | — |
| 1989 | 76° | 50° | 63° | — | — |
| 1988 | 92° | 58° | 75° | — | — |
| 1987 | 75° | 62° | 69° | 0.94" | — |
| 1986 | 70° | 44° | 57° | 0.51" | — |
| 1985 | 79° | 55° | 67° | — | — |
| 1984 | 71° | 43° | 57° | — | — |
| 1983 | 78° | 46° | 62° | 1.37" | — |
| 1982 | 69° | 48° | 59° | 2.97" | — |
| 1981coldest | 55° | 42° | 49° | 0.36" | — |
| 1980 | 66° | 45° | 55° | — | — |
| 1979 | 79° | 49° | 64° | — | — |
| 1978 | 81° | 61° | 71° | 1.02" | — |
| 1977 | 80° | 57° | 69° | 6.22" | — |
| 1976 | 75° | 52° | 63° | — | — |
| 1975 | 72° | 58° | 65° | 0.03" | — |
| 1974 | 83° | 50° | 66° | — | — |
| 1973 | 68° | 41° | 55° | 0.08" | — |
| 1971 | 71° | 54° | 62° | 0.18" | — |
54 years of data from JOLIET