Weather on March 21 at Isle Royale
Isle Royale National Park
Based on 51 years of data from Houghton, MI
Planning Your Visit
March 21st in Isle Royale National Park (via Houghton, MI) typically brings cold spring weather, with average highs around 34°F and lows near 19°F. Over 51 years of records, the warmest March 21st was in 2012 (59°F average), while the coldest was 1989 (9°F) — a 50°F range across recorded history. Precipitation has occurred on 37% of recorded March 21st dates, with snow falling 22% of the time (heaviest snowfall: 4.4"). The last decade has been 2.7°F warmer on this date compared to 20-30 years ago.
The last decade has been 2.7°F warmer on this date compared to 20-30 years ago.
Planning for March 21st in Isle Royale? Bundle up with warm layers and protect extremities from the cold. Consider bringing rain gear or an umbrella. Check road conditions if traveling, as snow is possible.
Year by Year History
| Year | High | Low | Precip | Snow |
|---|---|---|---|---|
| 2026 | 47°F | 29°F | 0.43" | -- |
| 2025 | 41°F | 19°F | 0" | -- |
| 2024 | 24°F | 11°F | 0" | -- |
| 2023 | 30°F | -1°F | 0" | -- |
| 2022 | 36°F | 27°F | 0" | -- |
| 2021 | 62°F | 44°F | 0" | -- |
| 2020 | 31°F | -2°F | 0" | -- |
| 2019 | 44°F | 32°F | 0" | -- |
| 2018 | 32°F | 8°F | 0" | -- |
| 2017 | 40°F | 19°F | 0" | -- |
| 2016 | 33°F | 10°F | 0" | -- |
| 2015 | 32°F | 13°F | 0" | -- |
| 2014 | 35°F | 10°F | 0" | -- |
| 2013 | 23°F | 7°F | 0" | -- |
| 2012 | 70°F | 48°F | 0" | -- |
| 2011 | 36°F | 31°F | 0.86" | -- |
| 2010 | 46°F | 22°F | 0" | -- |
| 2009 | 38°F | 27°F | 0.08" | -- |
| 2008 | 26°F | 2°F | 0" | -- |
| 2007 | 44°F | 31°F | 0.15" | -- |
| 2006 | 31°F | 21°F | 0" | -- |
| 2005 | 31°F | 10°F | 0" | -- |
| 2004 | 18°F | 1°F | 0" | -- |
| 2003 | 36°F | 31°F | 1.04" | -- |
| 2002 | 16°F | 4°F | 0.51" | 3" |
| 2001 | 53°F | 33°F | 0.15" | 0" |
| 2000 | 43°F | 34°F | 0.15" | 0" |
| 1999 | 35°F | 22°F | 0.25" | 1.5" |
| 1998 | 38°F | 17°F | 0" | 0" |
| 1997 | 35°F | 28°F | 0.18" | 1" |
| 1996 | 24°F | 9°F | 0" | 0" |
| 1995 | 36°F | 31°F | 1.09" | 3.7" |
| 1994 | 47°F | 32°F | 0.2" | 0.5" |
| 1993 | 23°F | 9°F | 0" | 0" |
| 1992 | 27°F | 8°F | 0" | 0" |
| 1991 | 33°F | 31°F | 1.07" | 4.4" |
| 1990 | 36°F | 27°F | 0.05" | 0.1" |
| 1989 | 18°F | 1°F | 0" | 0" |
| 1988 | 26°F | 0°F | 0" | 0" |
| 1982 | 33°F | 28°F | 0" | 0" |
| 1981 | 38°F | 26°F | 0" | 0" |
| 1980 | 27°F | 19°F | 0" | 0" |
| 1979 | 38°F | 32°F | 0" | 0" |
| 1978 | 34°F | 30°F | 0.15" | 0.6" |
| 1977 | 27°F | 17°F | 0" | 0" |
| 1976 | 17°F | 5°F | 0.79" | 3.7" |
| 1975 | 37°F | 28°F | 0.46" | 0" |
| 1974 | 19°F | 6°F | 0.23" | 0.9" |
| 1973 | 34°F | 19°F | 0" | 0" |
| 1972 | 35°F | 24°F | 1.96" | 2" |
| 1971 | 34°F | 10°F | 0" | 0" |