Weather on September 23 at Isle Royale
Isle Royale National Park
Based on 50 years of data from Houghton, MI
Planning Your Visit
September 23rd in Isle Royale National Park (via Houghton, MI) typically brings mild fall weather, with average highs around 61°F and lows near 43°F. Over 50 years of records, the warmest September 23rd was in 2017 (75°F average), while the coldest was 1989 (38°F) — a 37°F range across recorded history. Rain or other precipitation has occurred on about 34% of September 23rd dates historically, with the wettest September 23rd recording 2.67" of rain. The last decade has been 4.6°F warmer on this date compared to 20-30 years ago.
The last decade has been 4.6°F warmer on this date compared to 20-30 years ago.
Planning for September 23rd in Isle Royale? Great weather for outdoor activities. Consider bringing rain gear or an umbrella.
Year by Year History
| Year | High | Low | Precip | Snow |
|---|---|---|---|---|
| 2025 | 70°F | 54°F | 0" | -- |
| 2024 | 65°F | 40°F | 0" | -- |
| 2023 | 67°F | 61°F | 0.03" | -- |
| 2022 | 64°F | 33°F | 0" | -- |
| 2021 | 68°F | 38°F | 0" | -- |
| 2020 | 78°F | 45°F | 0" | -- |
| 2019 | 66°F | 47°F | 0.43" | -- |
| 2018 | 48°F | 42°F | 0.03" | -- |
| 2017 | 88°F | 62°F | 0" | -- |
| 2016 | 65°F | 49°F | 0" | -- |
| 2015 | 64°F | 41°F | 0" | -- |
| 2014 | 73°F | 48°F | 0" | -- |
| 2013 | 63°F | 40°F | 0" | -- |
| 2012 | 51°F | 41°F | 0" | -- |
| 2011 | 53°F | 46°F | 0" | -- |
| 2010 | 56°F | 52°F | 2.67" | -- |
| 2009 | 67°F | 46°F | 0" | -- |
| 2008 | 81°F | 57°F | 0" | -- |
| 2007 | 80°F | 44°F | 0" | -- |
| 2006 | 55°F | 49°F | 0.18" | -- |
| 2005 | 60°F | 33°F | 0" | -- |
| 2004 | 74°F | 53°F | 0" | -- |
| 2003 | 57°F | 44°F | 0.03" | -- |
| 2002 | 55°F | 38°F | 0.64" | 0" |
| 2001 | 66°F | 46°F | 0.28" | 0" |
| 2000 | 51°F | 42°F | 0.2" | 0" |
| 1999 | 67°F | 50°F | 0" | 0" |
| 1998 | 69°F | 36°F | 0" | 0" |
| 1997 | 64°F | 39°F | 0.05" | 0" |
| 1996 | 61°F | 51°F | 0" | 0" |
| 1995 | 59°F | 29°F | 0.03" | 0" |
| 1994 | 73°F | 60°F | 0.84" | 0" |
| 1993 | 57°F | 41°F | 0.05" | 0" |
| 1992 | 61°F | 32°F | 0" | 0" |
| 1991 | 50°F | 42°F | 0" | 0" |
| 1990 | 51°F | 39°F | 0" | 0" |
| 1989 | 43°F | 33°F | 0" | 0" |
| 1988 | 59°F | 49°F | 0" | 0" |
| 1983 | 51°F | 36°F | 0" | 0" |
| 1981 | 57°F | 34°F | 0" | 0" |
| 1980 | 50°F | 36°F | 0" | 0" |
| 1979 | 65°F | 42°F | 0" | 0" |
| 1978 | 70°F | 51°F | 0" | 0" |
| 1977 | 55°F | 53°F | 0.05" | 0" |
| 1976 | 45°F | 37°F | 0" | 0" |
| 1975 | 55°F | 42°F | 0.38" | 0" |
| 1974 | 57°F | 26°F | 0" | 0" |
| 1973 | 47°F | 43°F | 0.1" | 0" |
| 1972 | 65°F | 38°F | 0" | 0" |
| 1971 | 54°F | 41°F | 1.04" | 0" |