Weather on August 20 at Indiana Dunes
Indiana Dunes National Park
Based on 55 years of data from Gary, IN
Planning Your Visit
August 20th in Indiana Dunes National Park (via Gary, IN) typically brings warm summer weather, with average highs around 80°F and lows near 62°F. Over 55 years of records, the warmest August 20th was in 1983 (84°F average), while the coldest was 1992 (59°F) — a 25°F range across recorded history. Rain or other precipitation has occurred on about 36% of August 20th dates historically, with the wettest August 20th recording 5.21" of rain. The last decade has been 2.9°F warmer on this date compared to 20-30 years ago.
The last decade has been 2.9°F warmer on this date compared to 20-30 years ago.
Planning for August 20th in Indiana Dunes? Stay hydrated and seek shade during peak afternoon hours. Consider bringing rain gear or an umbrella.
Year by Year History
| Year | High | Low | Precip | Snow |
|---|---|---|---|---|
| 2025 | 79°F | 73°F | 0.03" | 0" |
| 2024 | 72°F | 50°F | 0" | 0" |
| 2023 | 77°F | 63°F | 0" | 0" |
| 2022 | 85°F | 64°F | -- | 0" |
| 2021 | 83°F | 66°F | 0" | 0" |
| 2020 | 75°F | 55°F | 0" | 0" |
| 2019 | 88°F | 70°F | 0" | 0" |
| 2018 | 80°F | 62°F | -- | -- |
| 2017 | 79°F | 60°F | 0" | 0" |
| 2016 | 81°F | 69°F | 0.89" | 0" |
| 2015 | 78°F | 57°F | 0.03" | 0" |
| 2014 | 82°F | 64°F | 0.03" | 0" |
| 2013 | 83°F | 62°F | 0" | 0" |
| 2012 | 74°F | 53°F | 0" | 0" |
| 2011 | 83°F | 59°F | 0" | 0" |
| 2010 | 88°F | 70°F | 0" | 0" |
| 2009 | 83°F | 60°F | 2.34" | 0" |
| 2008 | 78°F | 63°F | 0" | 0" |
| 2007 | 70°F | 59°F | 5.21" | 0" |
| 2006 | 79°F | 67°F | 0" | 0" |
| 2005 | 84°F | 71°F | 2.13" | 0" |
| 2004 | 68°F | 57°F | 0.2" | 0" |
| 2003 | 83°F | 61°F | 0" | 0" |
| 2002 | 70°F | 52°F | 0.33" | 0" |
| 2001 | 72°F | 64°F | 0.03" | 0" |
| 2000 | 71°F | 57°F | 0" | 0" |
| 1999 | 73°F | 54°F | 0" | 0" |
| 1998 | 82°F | 64°F | 0" | 0" |
| 1997 | 72°F | 61°F | 0.05" | 0" |
| 1996 | 86°F | 68°F | -- | 0" |
| 1995 | 88°F | 75°F | 0.28" | 0" |
| 1994 | 86°F | 67°F | 1.02" | 0" |
| 1993 | 80°F | 68°F | 0" | 0" |
| 1992 | 74°F | 45°F | 0" | 0" |
| 1991 | 74°F | 62°F | 0" | 0" |
| 1990 | 85°F | 67°F | 4.32" | 0" |
| 1989 | 84°F | 67°F | 1.47" | 0" |
| 1988 | 80°F | 66°F | 0" | 0" |
| 1987 | 88°F | 59°F | 0" | 0" |
| 1986 | 84°F | 54°F | 0" | 0" |
| 1985 | 71°F | 55°F | 0" | 0" |
| 1984 | 81°F | 50°F | 0" | 0" |
| 1983 | 96°F | 71°F | 0" | 0" |
| 1982 | 84°F | 67°F | 0.08" | 0" |
| 1981 | 78°F | 51°F | 0" | 0" |
| 1980 | 91°F | -- | 0.58" | 0" |
| 1979 | 77°F | 66°F | 1.83" | 0" |
| 1978 | 81°F | 54°F | 0" | 0" |
| 1977 | 74°F | 54°F | 0" | 0" |
| 1976 | 85°F | 56°F | 0" | 0" |
| 1975 | 77°F | 59°F | 0.51" | 0" |
| 1974 | 88°F | 62°F | 0" | 0" |
| 1973 | 80°F | 70°F | 0" | 0" |
| 1972 | 85°F | 64°F | 0" | 0" |
| 1971 | 91°F | 69°F | 0.13" | 0" |