Weather on August 21 at Indiana Dunes
Indiana Dunes National Park
Based on 55 years of data from Gary, IN
Planning Your Visit
August 21st in Indiana Dunes National Park (via Gary, IN) typically brings warm summer weather, with average highs around 81°F and lows near 61°F. Over 55 years of records, the warmest August 21st was in 1971 (80°F average), while the coldest was 2024 (59°F) — a 21°F range across recorded history. Rain or other precipitation has occurred on about 29% of August 21st dates historically, with the wettest August 21st recording 7.65" of rain. The last decade has been 2.6°F warmer on this date compared to 20-30 years ago.
The last decade has been 2.6°F warmer on this date compared to 20-30 years ago.
Planning for August 21st in Indiana Dunes? Stay hydrated and seek shade during peak afternoon hours.
Year by Year History
| Year | High | Low | Precip | Snow |
|---|---|---|---|---|
| 2025 | 77°F | 61°F | 0" | 0" |
| 2024 | 69°F | 49°F | 0" | 0" |
| 2023 | 86°F | 68°F | 0" | 0" |
| 2022 | 80°F | 63°F | -- | 0" |
| 2021 | 89°F | 69°F | -- | -- |
| 2020 | 84°F | 57°F | 0" | 0" |
| 2019 | 80°F | 62°F | 0.48" | 0" |
| 2018 | 77°F | 65°F | 7.65" | -- |
| 2017 | 87°F | 71°F | 0" | 0" |
| 2016 | 80°F | 59°F | 1.52" | 0" |
| 2015 | 73°F | 53°F | 0" | 0" |
| 2014 | 86°F | 67°F | 0.41" | 0" |
| 2013 | 85°F | 63°F | 0" | 0" |
| 2012 | 70°F | 53°F | 0.74" | 0" |
| 2011 | 77°F | 65°F | 0.74" | 0" |
| 2010 | 90°F | 70°F | 0.58" | 0" |
| 2009 | 78°F | 63°F | 0.46" | 0" |
| 2008 | 80°F | 63°F | 0" | 0" |
| 2007 | 74°F | 66°F | 0.71" | 0" |
| 2006 | 72°F | 55°F | 0" | 0" |
| 2005 | 84°F | 62°F | 0" | 0" |
| 2004 | 68°F | 52°F | 0.05" | 0" |
| 2003 | 88°F | 68°F | 0" | 0" |
| 2002 | 76°F | 61°F | 0" | 0" |
| 2001 | 74°F | 56°F | 0" | 0" |
| 2000 | 73°F | 54°F | 0" | 0" |
| 1999 | 75°F | 56°F | 0" | 0" |
| 1998 | 88°F | 68°F | 0" | 0" |
| 1997 | 72°F | 55°F | 0" | 0" |
| 1996 | 87°F | 69°F | -- | 0" |
| 1995 | 80°F | 64°F | 0" | 0" |
| 1994 | 77°F | 63°F | 0" | 0" |
| 1993 | 80°F | 47°F | 0" | 0" |
| 1992 | 78°F | 48°F | 0" | 0" |
| 1991 | 80°F | 52°F | 0" | 0" |
| 1990 | 74°F | 67°F | 0.25" | 0" |
| 1989 | 85°F | 61°F | 0" | 0" |
| 1988 | 80°F | 60°F | 0" | 0" |
| 1987 | 87°F | 59°F | 1.3" | 0" |
| 1986 | 81°F | 56°F | 0" | 0" |
| 1985 | 71°F | 56°F | 0" | 0" |
| 1984 | 85°F | 55°F | 0" | 0" |
| 1983 | 95°F | 64°F | 0" | 0" |
| 1982 | 80°F | 57°F | 0" | 0" |
| 1981 | 80°F | 55°F | 0" | 0" |
| 1980 | 90°F | -- | 0" | 0" |
| 1979 | 80°F | 66°F | 0.08" | 0" |
| 1978 | 83°F | 52°F | 0" | 0" |
| 1977 | 73°F | 59°F | 0.71" | 0" |
| 1976 | 86°F | 57°F | 0" | 0" |
| 1975 | 92°F | 68°F | 0.15" | 0" |
| 1974 | 88°F | 64°F | 0" | 0" |
| 1973 | 75°F | 62°F | 0" | 0" |
| 1972 | 89°F | 69°F | 0" | 0" |
| 1971 | 90°F | 70°F | 0.18" | 0" |