Weather on September 17 at Isle Royale
Isle Royale National Park
Based on 49 years of data from Houghton, MI
Planning Your Visit
September 17th in Isle Royale National Park (via Houghton, MI) typically brings mild fall weather, with average highs around 67°F and lows near 48°F. Over 49 years of records, the warmest September 17th was in 1979 (71°F average), while the coldest was 2020 (42°F) — a 29°F range across recorded history. Rain or other precipitation has occurred on about 33% of September 17th dates historically, with the wettest September 17th recording 2.87" of rain. The last decade has been 1.8°F warmer on this date compared to 20-30 years ago.
The last decade has been 1.8°F warmer on this date compared to 20-30 years ago.
Planning for September 17th 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 | 78°F | 58°F | 0" | -- |
| 2024 | 84°F | 58°F | 0" | -- |
| 2023 | 62°F | 47°F | 0" | -- |
| 2022 | 78°F | 63°F | 2.51" | -- |
| 2021 | 72°F | 50°F | 1.57" | -- |
| 2020 | 52°F | 32°F | 0" | -- |
| 2019 | 81°F | 61°F | 0" | -- |
| 2018 | 74°F | 51°F | 0" | -- |
| 2017 | 71°F | 50°F | 0.18" | -- |
| 2016 | 67°F | 55°F | 0.08" | -- |
| 2015 | 75°F | 66°F | 0.2" | -- |
| 2014 | 53°F | 32°F | 0" | -- |
| 2013 | 67°F | 41°F | 0" | -- |
| 2012 | 57°F | 39°F | 0.71" | -- |
| 2011 | 63°F | 36°F | 0" | -- |
| 2010 | 60°F | 46°F | 0" | -- |
| 2009 | 69°F | 50°F | 0" | -- |
| 2008 | 66°F | 44°F | 0" | -- |
| 2007 | 72°F | 45°F | 0.56" | -- |
| 2006 | 74°F | 54°F | 0.38" | -- |
| 2005 | 78°F | 47°F | 0" | -- |
| 2004 | 59°F | 37°F | 0" | -- |
| 2003 | 79°F | 53°F | 0" | -- |
| 2002 | 77°F | 54°F | 0" | 0" |
| 2001 | 67°F | 56°F | 0" | 0" |
| 2000 | 72°F | 55°F | 0" | 0" |
| 1999 | 71°F | 41°F | 0" | 0" |
| 1998 | 78°F | 54°F | 0" | 0" |
| 1997 | 67°F | 57°F | 2.87" | 0" |
| 1996 | 62°F | 47°F | 0" | 0" |
| 1995 | 65°F | 44°F | 0" | 0" |
| 1994 | 75°F | 49°F | 0.1" | 0" |
| 1993 | 58°F | 44°F | 0" | 0" |
| 1991 | 54°F | 50°F | 0.13" | 0" |
| 1990 | 55°F | 36°F | 0" | 0" |
| 1989 | 76°F | 49°F | 0" | 0" |
| 1988 | 67°F | 55°F | 0.03" | 0" |
| 1983 | 60°F | 46°F | 0.28" | 0" |
| 1981 | 54°F | 39°F | 0" | 0" |
| 1980 | 53°F | 34°F | 0.13" | 0" |
| 1979 | 82°F | 61°F | 0" | 0" |
| 1978 | 57°F | 50°F | 0.03" | 0" |
| 1977 | 64°F | 54°F | 0" | 0" |
| 1976 | 71°F | 47°F | 0" | 0" |
| 1975 | 67°F | 46°F | 0" | 0" |
| 1974 | 56°F | 40°F | 0.25" | 0" |
| 1973 | 55°F | 39°F | 0" | 0" |
| 1972 | 59°F | 48°F | 0" | 0" |
| 1971 | 60°F | 36°F | 0" | 0" |