Weather on September 21 at Mammoth Cave
Mammoth Cave National Park
Based on 55 years of data from Bowling Green, KY
Planning Your Visit
September 21st in Mammoth Cave National Park (via Bowling Green, KY) typically brings warm fall weather, with average highs around 81°F and lows near 58°F. Over 55 years of records, the warmest September 21st was in 2022 (83°F average), while the coldest was 1983 (52°F) — a 31°F range across recorded history. Rain or other precipitation has occurred on about 35% of September 21st dates historically, with the wettest September 21st recording 7.39" of rain. The last decade has been 8.5°F warmer on this date compared to 20-30 years ago.
The last decade has been 8.5°F warmer on this date compared to 20-30 years ago.
Planning for September 21st in Mammoth Cave? 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 | 80°F | 67°F | 1.32" | 0" |
| 2024 | 93°F | 70°F | 0.28" | 0" |
| 2023 | 85°F | 61°F | 0" | 0" |
| 2022 | 97°F | 69°F | 0" | -- |
| 2021 | 83°F | 66°F | 1.83" | 0" |
| 2020 | 76°F | 50°F | 0" | 0" |
| 2019 | 91°F | 64°F | 0" | 0" |
| 2018 | 91°F | 74°F | 0.33" | 0" |
| 2017 | 90°F | 66°F | 0" | 0" |
| 2016 | 89°F | 61°F | 0" | 0" |
| 2015 | 79°F | 52°F | 0" | 0" |
| 2014 | 83°F | 61°F | 0" | 0" |
| 2013 | 73°F | 54°F | 1.57" | 0" |
| 2012 | 81°F | 56°F | 0" | 0" |
| 2011 | 82°F | 62°F | 0.1" | 0" |
| 2010 | 98°F | 64°F | 0" | 0" |
| 2009 | 80°F | 67°F | 0.97" | 0" |
| 2008 | 87°F | 61°F | 0" | 0" |
| 2007 | 89°F | 55°F | 0" | 0" |
| 2006 | 69°F | 44°F | 0" | 0" |
| 2005 | 89°F | 63°F | 0" | 0" |
| 2004 | 79°F | 47°F | 0" | 0" |
| 2003 | 81°F | 54°F | 2.54" | 0" |
| 2002 | 78°F | 65°F | 0" | 0" |
| 2001 | 80°F | 55°F | 0" | 0" |
| 2000 | 70°F | 54°F | 0.18" | 0" |
| 1999 | 70°F | 54°F | 0.18" | 0" |
| 1998 | 89°F | 70°F | 0.03" | 0" |
| 1997 | 74°F | 54°F | -- | 0" |
| 1996 | 70°F | 57°F | -- | 0" |
| 1995 | 80°F | 60°F | 0" | 0" |
| 1994 | 83°F | 54°F | 0" | 0" |
| 1993 | 83°F | 56°F | 0" | 0" |
| 1992 | 86°F | 68°F | 4.27" | 0" |
| 1991 | 70°F | 42°F | 0" | 0" |
| 1990 | 81°F | 59°F | 7.39" | 0" |
| 1989 | 86°F | 59°F | 0" | 0" |
| 1988 | 80°F | 52°F | 0" | 0" |
| 1987 | 77°F | 53°F | 0" | 0" |
| 1986 | 89°F | 64°F | 0.03" | 0" |
| 1985 | 85°F | 57°F | 0" | 0" |
| 1984 | 87°F | 50°F | 0" | 0" |
| 1983 | 60°F | 44°F | 0.28" | 0" |
| 1982 | 64°F | 49°F | 0" | 0" |
| 1981 | 77°F | 45°F | 0" | 0" |
| 1980 | 83°F | 73°F | 1.42" | 0" |
| 1979 | 72°F | 60°F | 6.3" | 0" |
| 1978 | 90°F | 68°F | 0.76" | 0" |
| 1977 | 76°F | 52°F | 0" | 0" |
| 1976 | 75°F | 52°F | 0" | 0" |
| 1975 | 71°F | 49°F | 0" | 0" |
| 1974 | 70°F | 53°F | 1.47" | 0" |
| 1973 | 85°F | 61°F | 0" | 0" |
| 1972 | 90°F | 57°F | 0" | 0" |
| 1971 | 73°F | 53°F | 0" | 0" |