Weather on May 18 at Isle Royale
Isle Royale National Park
Based on 50 years of data from Houghton, MI
Planning Your Visit
May 18th in Isle Royale National Park (via Houghton, MI) typically brings mild spring weather, with average highs around 64°F and lows near 42°F. Over 50 years of records, the warmest May 18th was in 1989 (70°F average), while the coldest was 2002 (34°F) — a 36°F range across recorded history. Rain or other precipitation has occurred on about 36% of May 18th dates historically, with the wettest May 18th recording 2.01" of rain. The last decade has been 3.6°F cooler on this date compared to 20-30 years ago.
The last decade has been 3.6°F cooler on this date compared to 20-30 years ago.
Planning for May 18th 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 | 38°F | 34°F | 0.05" | -- |
| 2024 | 83°F | 46°F | 0.66" | -- |
| 2023 | 68°F | 35°F | 0.43" | -- |
| 2022 | 63°F | 37°F | 1.37" | -- |
| 2021 | 80°F | 48°F | 0" | -- |
| 2020 | 61°F | 44°F | 0" | -- |
| 2019 | 43°F | 37°F | 0.94" | -- |
| 2018 | 64°F | 39°F | 0" | -- |
| 2017 | 47°F | 33°F | 1.17" | -- |
| 2016 | 65°F | 33°F | 0" | -- |
| 2015 | 61°F | 32°F | 0.08" | -- |
| 2014 | 71°F | 45°F | 0" | -- |
| 2013 | 51°F | 42°F | 2.01" | -- |
| 2012 | 82°F | 53°F | 0.13" | -- |
| 2011 | 61°F | 37°F | 0" | -- |
| 2010 | 75°F | 41°F | 0" | -- |
| 2009 | 70°F | 39°F | 0.03" | -- |
| 2008 | 48°F | 35°F | 0.05" | -- |
| 2007 | 72°F | 42°F | 0" | -- |
| 2006 | 51°F | 39°F | 0" | -- |
| 2005 | 59°F | 39°F | 0" | -- |
| 2004 | 64°F | 37°F | 0" | -- |
| 2003 | 65°F | 43°F | 0" | 0" |
| 2002 | 43°F | 26°F | 0" | 0" |
| 2001 | 76°F | 54°F | 0" | 0" |
| 2000 | 64°F | 42°F | 0" | 0" |
| 1999 | 57°F | 45°F | 2.01" | 0" |
| 1998 | 83°F | 57°F | 1.63" | 0" |
| 1997 | 56°F | 39°F | 0" | 0" |
| 1996 | 81°F | 42°F | 0.1" | 0" |
| 1995 | 69°F | 43°F | 0" | 0" |
| 1994 | 60°F | 35°F | 0" | 0" |
| 1993 | 52°F | 38°F | 0" | 0" |
| 1992 | 56°F | 37°F | 0" | 0" |
| 1991 | 48°F | 36°F | 0" | 0" |
| 1990 | 50°F | 38°F | 0.48" | 0" |
| 1989 | 81°F | 59°F | 0.36" | 0" |
| 1988 | 65°F | 34°F | 0" | 0" |
| 1982 | 73°F | 51°F | 0.51" | 0" |
| 1981 | 62°F | 33°F | 0" | 0" |
| 1980 | 70°F | 46°F | 0" | 0" |
| 1979 | 68°F | 54°F | 0" | 0" |
| 1978 | 82°F | 50°F | 0" | 0" |
| 1977 | 78°F | 55°F | 0" | 0" |
| 1976 | 57°F | 36°F | 0" | 0" |
| 1975 | 77°F | 56°F | 0" | 0" |
| 1974 | 52°F | 41°F | 0" | 0" |
| 1973 | 55°F | 39°F | 0" | 0" |
| 1972 | 66°F | 48°F | 0" | 0" |
| 1971 | 57°F | 36°F | 1.02" | 0" |