Weather on December 18 at Isle Royale
Isle Royale National Park
Based on 50 years of data from Houghton, MI
Planning Your Visit
December 18th in Isle Royale National Park (via Houghton, MI) typically brings very cold winter weather, with average highs around 27°F and lows near 14°F. Over 50 years of records, the warmest December 18th was in 1997 (38°F average), while the coldest was 2016 (0°F) — a 38°F range across recorded history. Precipitation has occurred on 52% of recorded December 18th dates, with snow falling 30% of the time (heaviest snowfall: 10.3"). The last decade has been 2.8°F cooler on this date compared to 20-30 years ago.
The last decade has been 2.8°F cooler on this date compared to 20-30 years ago.
Planning for December 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 |
|---|---|---|---|---|
| 2025 | 42°F | 13°F | 0.23" | -- |
| 2024 | 28°F | 15°F | 0.08" | -- |
| 2023 | 32°F | 15°F | 0.03" | -- |
| 2022 | 30°F | 18°F | 0" | -- |
| 2021 | 25°F | 19°F | 0.08" | -- |
| 2020 | 34°F | 19°F | 0" | -- |
| 2019 | 9°F | -4°F | 0" | -- |
| 2018 | 36°F | 15°F | 0" | -- |
| 2017 | 37°F | 25°F | 0.08" | -- |
| 2016 | 6°F | -7°F | 0" | -- |
| 2015 | 25°F | 17°F | 0.23" | -- |
| 2014 | 27°F | 0°F | 0" | -- |
| 2013 | 40°F | 12°F | 0" | -- |
| 2012 | 30°F | 18°F | 0" | -- |
| 2011 | 39°F | 24°F | 0" | -- |
| 2010 | 21°F | 17°F | 0" | -- |
| 2009 | 29°F | 17°F | 0" | -- |
| 2008 | 17°F | -2°F | 0.08" | -- |
| 2007 | 31°F | 21°F | 0.18" | -- |
| 2006 | 27°F | 17°F | 0" | -- |
| 2005 | 18°F | 12°F | 0.1" | -- |
| 2004 | 30°F | -3°F | 0.1" | -- |
| 2003 | 27°F | 22°F | 0" | -- |
| 2002 | 40°F | 30°F | 0.28" | 0" |
| 2001 | 37°F | 24°F | 0" | 0" |
| 2000 | 19°F | 13°F | 0.23" | 4.5" |
| 1999 | 26°F | 1°F | 0" | 0" |
| 1998 | 30°F | 13°F | 0.64" | 3.2" |
| 1997 | 46°F | 31°F | 0" | 0" |
| 1996 | 30°F | 22°F | 0.28" | 1.3" |
| 1995 | 33°F | 23°F | 0" | 0" |
| 1994 | 31°F | 26°F | 0" | 0" |
| 1993 | 36°F | 28°F | 0.56" | 1.4" |
| 1992 | 24°F | 16°F | 0.41" | 2.6" |
| 1991 | 14°F | 1°F | 0.13" | 0.9" |
| 1990 | 27°F | 14°F | 0.15" | 2.6" |
| 1989 | 19°F | 3°F | 1.45" | 10.3" |
| 1988 | 25°F | 8°F | 0.43" | 2.9" |
| 1987 | 28°F | 20°F | 0.08" | 3" |
| 1981 | 19°F | 14°F | 1.42" | 8.4" |
| 1980 | 17°F | -5°F | 0.64" | 3.7" |
| 1979 | 23°F | 13°F | 0" | 0" |
| 1978 | 26°F | 12°F | 0" | 0" |
| 1977 | 35°F | 31°F | 0.84" | 2.6" |
| 1976 | 35°F | 19°F | 0" | 0" |
| 1975 | 6°F | -2°F | 1.19" | 5.5" |
| 1974 | 24°F | 18°F | 0" | 0" |
| 1973 | 13°F | 4°F | 0" | 0" |
| 1972 | 25°F | 19°F | 0" | 0" |
| 1971 | 17°F | 0°F | 0.05" | 1" |