Weather on September 18 at Indiana Dunes
Indiana Dunes National Park
Based on 55 years of data from Gary, IN
Planning Your Visit
September 18th in Indiana Dunes National Park (via Gary, IN) typically brings pleasant fall weather, with average highs around 76°F and lows near 55°F. Over 55 years of records, the warmest September 18th was in 1988 (79°F average), while the coldest was 1981 (53°F) — a 26°F range across recorded history. Rain or other precipitation has occurred on about 36% of September 18th dates historically, with the wettest September 18th recording 6.78" of rain. The last decade has been 4.3°F warmer on this date compared to 20-30 years ago.
The last decade has been 4.3°F warmer on this date compared to 20-30 years ago.
Planning for September 18th in Indiana Dunes? Great weather for outdoor activities. Consider bringing rain gear or an umbrella.
Year by Year History
| Year | High | Low | Precip | Snow |
|---|---|---|---|---|
| 2025 | 83°F | 56°F | 0" | 0" |
| 2024 | 78°F | 56°F | 0" | 0" |
| 2023 | 68°F | 54°F | 0.56" | 0" |
| 2022 | 84°F | 67°F | 0" | 0" |
| 2021 | 79°F | 65°F | -- | -- |
| 2020 | 61°F | 45°F | -- | -- |
| 2019 | 79°F | 59°F | 0" | 0" |
| 2018 | 89°F | 64°F | 0" | -- |
| 2017 | 88°F | 59°F | 1.07" | 0" |
| 2016 | 81°F | 59°F | 0" | 0" |
| 2015 | 84°F | 65°F | 6.78" | 0" |
| 2014 | 67°F | 44°F | 0" | 0" |
| 2013 | 71°F | 56°F | 0" | 0" |
| 2012 | 75°F | 55°F | 0.3" | 0" |
| 2011 | 71°F | 53°F | 0" | 0" |
| 2010 | 74°F | 56°F | 0" | 0" |
| 2009 | 69°F | 45°F | 0" | 0" |
| 2008 | 80°F | 57°F | 0" | 0" |
| 2007 | 78°F | 55°F | 0" | 0" |
| 2006 | 83°F | 57°F | 0.84" | 0" |
| 2005 | 71°F | 53°F | 0" | 0" |
| 2004 | 68°F | 51°F | 0" | 0" |
| 2003 | 82°F | 56°F | 0" | 0" |
| 2002 | 78°F | 59°F | 0.15" | 0" |
| 2001 | 69°F | 55°F | 0.15" | 0" |
| 2000 | 77°F | 53°F | 0" | 0" |
| 1999 | 71°F | 49°F | 0" | 0" |
| 1998 | 82°F | 57°F | 0" | 0" |
| 1997 | 82°F | 58°F | -- | 0" |
| 1996 | 68°F | 45°F | 0" | 0" |
| 1995 | 69°F | 40°F | -- | 0" |
| 1994 | 70°F | 48°F | 0" | 0" |
| 1993 | 66°F | 44°F | 0" | 0" |
| 1992 | 78°F | 66°F | 0.38" | 0" |
| 1991 | 75°F | 53°F | 0.08" | 0" |
| 1990 | 64°F | 47°F | 0.05" | 0" |
| 1989 | 76°F | 49°F | 0" | 0" |
| 1988 | 88°F | 70°F | 0" | 0" |
| 1987 | 71°F | 61°F | 0.43" | 0" |
| 1986 | 72°F | 59°F | 0.36" | 0" |
| 1985 | 87°F | 67°F | 0" | 0" |
| 1984 | 76°F | 43°F | 0" | 0" |
| 1983 | 90°F | 61°F | 0.28" | 0" |
| 1982 | 62°F | 51°F | 2.95" | 0" |
| 1981 | 60°F | 47°F | 2.08" | 0" |
| 1980 | 74°F | 38°F | 0" | 0" |
| 1979 | 78°F | 53°F | 0" | 0" |
| 1978 | 85°F | 64°F | 2.21" | 0" |
| 1977 | 80°F | 66°F | 3.73" | 0" |
| 1976 | 75°F | 50°F | 0" | 0" |
| 1975 | 79°F | 55°F | 0" | 0" |
| 1974 | 81°F | 50°F | 0" | 0" |
| 1973 | 67°F | 45°F | 0.13" | 0" |
| 1972 | 87°F | 62°F | 0.94" | 0" |
| 1971 | 68°F | 51°F | 0.05" | 0" |