Weather on August 18 at Isle Royale
Isle Royale National Park
Based on 50 years of data from Houghton, MI
Planning Your Visit
August 18th in Isle Royale National Park (via Houghton, MI) typically brings pleasant summer weather, with average highs around 73°F and lows near 55°F. Over 50 years of records, the warmest August 18th was in 2021 (76°F average), while the coldest was 2007 (52°F) — a 24°F range across recorded history. Rain or other precipitation has occurred on about 30% of August 18th dates historically, with the wettest August 18th recording 1.42" of rain. The last decade has been 1.6°F warmer on this date compared to 20-30 years ago.
The last decade has been 1.6°F warmer on this date compared to 20-30 years ago.
Planning for August 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 | 68°F | 54°F | 0.13" | -- |
| 2024 | 71°F | 57°F | 0" | -- |
| 2023 | 76°F | 46°F | 0" | -- |
| 2022 | 82°F | 58°F | 0" | -- |
| 2021 | 90°F | 62°F | 0" | -- |
| 2020 | 70°F | 52°F | 0" | -- |
| 2019 | 69°F | 58°F | 1.27" | -- |
| 2018 | 73°F | 54°F | 0" | -- |
| 2017 | 67°F | 57°F | 0.13" | -- |
| 2016 | 84°F | 59°F | 0.18" | -- |
| 2015 | 70°F | 57°F | 0.13" | -- |
| 2014 | 61°F | 51°F | 0.38" | -- |
| 2013 | 79°F | 58°F | 0" | -- |
| 2012 | 68°F | 47°F | 0" | -- |
| 2011 | 80°F | 62°F | 0" | -- |
| 2010 | 65°F | 52°F | 1.42" | -- |
| 2009 | 66°F | 50°F | 0.13" | -- |
| 2008 | 77°F | 50°F | 0.03" | -- |
| 2007 | 68°F | 35°F | 0" | -- |
| 2006 | 76°F | 59°F | 0" | -- |
| 2005 | 75°F | 59°F | 0.2" | -- |
| 2004 | 71°F | 48°F | 0" | -- |
| 2003 | 89°F | 61°F | 0" | 0" |
| 2002 | 67°F | 57°F | 0" | 0" |
| 2001 | 77°F | 61°F | 0" | 0" |
| 2000 | 65°F | 55°F | 0.38" | 0" |
| 1999 | 63°F | 49°F | 0" | 0" |
| 1998 | 68°F | 49°F | 0" | 0" |
| 1997 | 69°F | 47°F | 0" | 0" |
| 1996 | 84°F | 59°F | 0" | 0" |
| 1995 | 83°F | 66°F | 0.1" | 0" |
| 1994 | 78°F | 53°F | 0" | 0" |
| 1993 | 81°F | 60°F | 0" | 0" |
| 1992 | 66°F | 52°F | 0.03" | 0" |
| 1991 | 60°F | 53°F | 0" | 0" |
| 1990 | 64°F | 58°F | 0" | 0" |
| 1989 | 78°F | 53°F | 0" | 0" |
| 1988 | 66°F | 49°F | 0" | 0" |
| 1983 | 83°F | 61°F | 0.15" | 0" |
| 1981 | 72°F | 52°F | 0" | 0" |
| 1980 | 72°F | 60°F | 0" | 0" |
| 1979 | 74°F | 50°F | 0" | 0" |
| 1978 | 76°F | 62°F | 0.53" | 0" |
| 1977 | 64°F | 43°F | 0" | 0" |
| 1976 | 85°F | 58°F | 0" | 0" |
| 1975 | 65°F | 44°F | 0" | 0" |
| 1974 | 71°F | 56°F | 0" | 0" |
| 1973 | 82°F | 61°F | 0" | 0" |
| 1972 | 82°F | 63°F | 0" | 0" |
| 1971 | 84°F | 62°F | 0" | 0" |