Weather on March 18 at Isle Royale
Isle Royale National Park
Based on 51 years of data from Houghton, MI
Planning Your Visit
March 18th in Isle Royale National Park (via Houghton, MI) typically brings cold spring weather, with average highs around 35°F and lows near 20°F. Over 51 years of records, the warmest March 18th was in 2012 (63°F average), while the coldest was 1989 (9°F) — a 54°F range across recorded history. Precipitation has occurred on 35% of recorded March 18th dates, with snow falling 22% of the time (heaviest snowfall: 3.9"). The last decade has been 1.1°F cooler on this date compared to 20-30 years ago.
The last decade has been 1.1°F cooler on this date compared to 20-30 years ago.
Planning for March 18th 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 | 34°F | 15°F | 0" | -- |
| 2025 | 39°F | 27°F | 0" | -- |
| 2024 | 27°F | 20°F | 0" | -- |
| 2023 | 23°F | 14°F | 0.03" | -- |
| 2022 | 35°F | 29°F | 0" | -- |
| 2021 | 38°F | 25°F | 0" | -- |
| 2020 | 39°F | 17°F | 0" | -- |
| 2019 | 36°F | 10°F | 0" | -- |
| 2018 | 37°F | 17°F | 0" | -- |
| 2017 | 34°F | 27°F | 0.05" | -- |
| 2016 | 29°F | 19°F | 0" | -- |
| 2015 | 31°F | 19°F | 0" | -- |
| 2014 | 26°F | 21°F | 0" | -- |
| 2013 | 31°F | 12°F | 0.43" | -- |
| 2012 | 76°F | 51°F | 0" | -- |
| 2011 | 38°F | 20°F | 0.03" | -- |
| 2010 | 51°F | 40°F | 0" | -- |
| 2009 | 38°F | 18°F | 0" | -- |
| 2008 | 31°F | 27°F | 0.74" | -- |
| 2007 | 36°F | 13°F | 0.18" | -- |
| 2006 | 28°F | 16°F | 0" | -- |
| 2005 | 25°F | -2°F | 0" | -- |
| 2004 | 37°F | 16°F | 0" | -- |
| 2003 | 31°F | 26°F | 0" | -- |
| 2002 | 40°F | 20°F | 0" | 0" |
| 2001 | 49°F | 15°F | 0" | 0" |
| 2000 | 43°F | 23°F | 0" | 0" |
| 1999 | 41°F | 29°F | 0.03" | 0.1" |
| 1998 | 34°F | 30°F | 0" | 0" |
| 1997 | 35°F | 7°F | 0" | 0" |
| 1996 | 40°F | 27°F | 0.03" | 0.2" |
| 1995 | 38°F | 29°F | 0.05" | 0" |
| 1994 | 31°F | 20°F | 0.48" | 3.9" |
| 1993 | 28°F | -2°F | 0" | 0" |
| 1992 | 28°F | 10°F | 0" | 0" |
| 1991 | 38°F | 32°F | 0" | 0" |
| 1990 | 25°F | 15°F | 0.36" | 2.7" |
| 1989 | 17°F | 0°F | 0" | 0" |
| 1988 | 29°F | 21°F | 0.18" | 1.4" |
| 1982 | 34°F | 22°F | 0.13" | 0.5" |
| 1981 | 22°F | 16°F | 0.3" | 2.3" |
| 1980 | 30°F | 15°F | 0" | 0" |
| 1979 | 42°F | 34°F | 0" | 0" |
| 1978 | 36°F | 11°F | 0.3" | 1.2" |
| 1977 | 32°F | 22°F | 0" | 0" |
| 1976 | 36°F | 22°F | 0.08" | 0.3" |
| 1975 | 47°F | 34°F | 0" | 0" |
| 1974 | 31°F | 15°F | 0.25" | 1" |
| 1973 | 28°F | 17°F | 0" | 0" |
| 1972 | 23°F | 10°F | 0.08" | 0.5" |
| 1971 | 37°F | 19°F | 0" | 0" |