Weather on August 18
Joliet, IL
55 Years of Data
Avg High
82°F
Avg Low
62°F
Warmest
1988
90°F avg
Coldest
1981
63°F avg
About This Date
August 18th in Joliet, IL typically brings warm summer weather, with average highs around 82°F and lows near 62°F. Over 53 years of records, the warmest August 18th was in 1988 (90°F average), while the coldest was 1981 (63°F) — a 27°F range across recorded history. Rain or other precipitation has occurred on about 38% of August 18th dates historically, with the wettest August 18th recording 3.28" of rain. The last decade has been 2.0°F warmer on this date compared to 20-30 years ago.
The last decade has been 2.0°F warmer on this date compared to 20-30 years ago.
Planning for August 18th in Joliet, IL? Stay hydrated and seek shade during peak afternoon hours. Consider bringing rain gear or an umbrella.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 87° | 73° | 80° | — | — |
| 2024 | 81° | 62° | 71° | 0.25" | — |
| 2023 | 78° | 55° | 67° | 0.64" | — |
| 2022 | 83° | 59° | 71° | — | — |
| 2021 | 85° | 65° | 75° | — | — |
| 2020 | 83° | 61° | 72° | 0.25" | — |
| 2019 | 83° | 63° | 73° | 0.56" | — |
| 2018 | 81° | 68° | 74° | 0.53" | — |
| 2017 | 80° | 63° | 71° | 0.13" | — |
| 2016 | 85° | 69° | 77° | — | — |
| 2015 | 85° | 67° | 76° | 1.75" | — |
| 2014 | 77° | 62° | 70° | — | — |
| 2013 | 81° | 58° | 69° | — | — |
| 2012 | 75° | 55° | 65° | — | — |
| 2011 | 83° | 62° | 72° | — | — |
| 2010 | 76° | 65° | 70° | 0.08" | — |
| 2009 | 87° | 55° | 71° | 1.78" | — |
| 2008 | 83° | 60° | 71° | — | — |
| 2007 | 79° | 62° | 70° | — | — |
| 2006 | 82° | 62° | 72° | — | — |
| 2005 | 71° | 65° | 68° | — | — |
| 2004 | 82° | 61° | 71° | 0.03" | — |
| 2003 | 85° | 65° | 75° | — | — |
| 2002 | 87° | 55° | 71° | — | — |
| 2001 | 78° | 58° | 68° | — | — |
| 2000 | 82° | 61° | 71° | 2.54" | — |
| 1999 | 87° | 55° | 71° | — | — |
| 1998 | 83° | 69° | 76° | — | — |
| 1997 | 75° | 62° | 69° | 0.13" | — |
| 1996 | 77° | 65° | 71° | — | — |
| 1995 | 89° | 73° | 81° | 0.05" | — |
| 1994 | 81° | 58° | 69° | — | — |
| 1993 | 84° | 69° | 77° | — | — |
| 1992 | 77° | 53° | 65° | — | — |
| 1991 | 88° | 60° | 74° | — | — |
| 1990 | 77° | 69° | 73° | 1.42" | — |
| 1989 | 78° | 58° | 68° | — | — |
| 1988warmest | 101° | 79° | 90° | — | — |
| 1986 | 88° | 60° | 74° | — | — |
| 1985 | 84° | 65° | 74° | 0.08" | — |
| 1984 | 76° | 62° | 69° | 0.38" | — |
| 1983 | 90° | 67° | 78° | 1.57" | — |
| 1982 | 82° | 55° | 69° | — | — |
| 1981coldest | 73° | 53° | 63° | — | — |
| 1980 | 80° | 60° | 70° | 0.43" | — |
| 1979 | 79° | 59° | 69° | 3.28" | — |
| 1978 | 84° | 63° | 73° | 0.2" | — |
| 1977 | 79° | 51° | 65° | — | — |
| 1976 | 79° | 58° | 68° | — | — |
| 1974 | 89° | 60° | 75° | — | — |
| 1973 | 88° | 66° | 77° | — | — |
| 1972 | 96° | 72° | 84° | — | — |
| 1971 | 86° | 57° | 72° | — | — |
53 years of data from JOLIET