Weather on October 21 at Isle Royale
Isle Royale National Park
Based on 50 years of data from Houghton, MI
Planning Your Visit
October 21st in Isle Royale National Park (via Houghton, MI) typically brings cool fall weather, with average highs around 50°F and lows near 37°F. Over 50 years of records, the warmest October 21st was in 2017 (66°F average), while the coldest was 1981 (29°F) — a 37°F range across recorded history. Precipitation has occurred on 54% of recorded October 21st dates, with snow falling 14% of the time (heaviest snowfall: 1.7"). 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 October 21st in Isle Royale? Bring layers as temperatures can vary throughout the day. Consider bringing rain gear or an umbrella.
Year by Year History
| Year | High | Low | Precip | Snow |
|---|---|---|---|---|
| 2025 | 51°F | 44°F | 2.11" | -- |
| 2024 | 69°F | 52°F | 0" | -- |
| 2023 | 44°F | 30°F | 0" | -- |
| 2022 | 59°F | 37°F | 0" | -- |
| 2021 | 46°F | 38°F | 0" | -- |
| 2020 | 40°F | 33°F | 0.61" | -- |
| 2019 | 52°F | 47°F | 1.22" | -- |
| 2018 | 41°F | 26°F | 0" | -- |
| 2017 | 71°F | 61°F | 0.08" | -- |
| 2016 | 45°F | 28°F | 0" | -- |
| 2015 | 61°F | 43°F | 0.08" | -- |
| 2014 | 46°F | 33°F | 0" | -- |
| 2013 | 39°F | 31°F | 1.24" | -- |
| 2012 | 55°F | 33°F | 0.03" | -- |
| 2011 | 48°F | 36°F | 0" | -- |
| 2010 | 44°F | 35°F | 0.03" | -- |
| 2009 | 40°F | 33°F | 1.96" | -- |
| 2008 | 44°F | 31°F | 0" | -- |
| 2007 | 59°F | 45°F | 0.03" | -- |
| 2006 | 38°F | 33°F | 0.03" | -- |
| 2005 | 48°F | 26°F | 0.1" | -- |
| 2004 | 56°F | 41°F | 0" | -- |
| 2003 | 46°F | 36°F | 0.13" | -- |
| 2002 | 34°F | 30°F | 0.3" | 0.3" |
| 2001 | 52°F | 40°F | 0.05" | 0" |
| 2000 | 62°F | 34°F | 0" | 0" |
| 1999 | 65°F | 40°F | 0" | 0" |
| 1998 | 44°F | 35°F | 0.33" | 0" |
| 1997 | 38°F | 29°F | 0.76" | 1.7" |
| 1996 | 62°F | 39°F | 0" | 0" |
| 1995 | 44°F | 34°F | 2.59" | 0.2" |
| 1994 | 63°F | 34°F | 0" | 0" |
| 1993 | 41°F | 35°F | 1.47" | 0.3" |
| 1992 | 45°F | 33°F | 0" | 0" |
| 1991 | 46°F | 33°F | 0.38" | 0" |
| 1990 | 43°F | 38°F | 0.03" | 0" |
| 1989 | 44°F | 32°F | 0" | 0" |
| 1988 | 44°F | 37°F | 0.41" | 0" |
| 1983 | 51°F | 32°F | 0" | 0" |
| 1981 | 32°F | 26°F | 0.13" | 0.5" |
| 1980 | 38°F | 32°F | 0" | 0" |
| 1979 | 61°F | 41°F | 0.46" | 0" |
| 1978 | 73°F | 49°F | 0" | 0" |
| 1977 | 57°F | 40°F | 0" | 0" |
| 1976 | 41°F | 32°F | 0.08" | 0.3" |
| 1975 | 55°F | 47°F | 0" | 0" |
| 1974 | 58°F | 28°F | 0" | 0" |
| 1973 | 71°F | 41°F | 0" | 0" |
| 1972 | 41°F | 33°F | 0.89" | 0.5" |
| 1971 | 59°F | 50°F | 0.33" | 0" |