Weather on July 21 at Isle Royale
Isle Royale National Park
MIMidwest800 ft elevation
Avg High76°F
Avg Low55°F
Warmest200281°F
Coldest198154°F
Based on 50 years of data from Houghton, MI
Planning Your Visit
July 21st in Isle Royale National Park (via Houghton, MI) typically brings pleasant summer weather, with average highs around 76°F and lows near 55°F. Over 50 years of records, the warmest July 21st was in 2002 (81°F average), while the coldest was 1981 (54°F) — a 27°F range across recorded history. Rain or other precipitation has occurred on about 24% of July 21st dates historically, with the wettest July 21st recording 3.76" of rain. The last decade has been 3.8°F cooler on this date compared to 20-30 years ago.
The last decade has been 3.8°F cooler on this date compared to 20-30 years ago.
Planning for July 21st in Isle Royale? Great weather for outdoor activities.
Year by Year History
| Year | High | Low | Precip | Snow |
|---|---|---|---|---|
| 2025 | 76°F | 50°F | 0" | -- |
| 2024 | 75°F | 51°F | 0" | -- |
| 2023 | 79°F | 58°F | 0" | -- |
| 2022 | 79°F | 62°F | 0" | -- |
| 2021 | 75°F | 45°F | 0" | -- |
| 2020 | 65°F | 49°F | 3.45" | -- |
| 2019 | 71°F | 53°F | 0" | -- |
| 2018 | 70°F | 59°F | 0" | -- |
| 2017 | 80°F | 56°F | 0" | -- |
| 2016 | 85°F | 67°F | 3.15" | -- |
| 2015 | 71°F | 53°F | 0" | -- |
| 2014 | 89°F | 69°F | 0" | -- |
| 2013 | 67°F | 43°F | 0" | -- |
| 2012 | 77°F | 57°F | 0.3" | -- |
| 2011 | 79°F | 63°F | 0" | -- |
| 2010 | 75°F | 55°F | 0" | -- |
| 2009 | 78°F | 56°F | 0" | -- |
| 2008 | 71°F | 53°F | 0.36" | -- |
| 2007 | 74°F | 43°F | 0" | -- |
| 2006 | 76°F | 51°F | 0" | -- |
| 2005 | 75°F | 54°F | 0" | -- |
| 2004 | 83°F | 56°F | 0" | -- |
| 2003 | 65°F | 53°F | 0" | -- |
| 2002 | 89°F | 73°F | 0" | 0" |
| 2001 | 89°F | 66°F | 0" | 0" |
| 2000 | 68°F | 53°F | 0.1" | 0" |
| 1999 | 84°F | 59°F | 0" | 0" |
| 1998 | 87°F | 72°F | 0" | 0" |
| 1997 | 68°F | 55°F | 0" | 0" |
| 1996 | 77°F | 50°F | 0" | 0" |
| 1995 | 82°F | 55°F | 0" | 0" |
| 1994 | 85°F | 63°F | 1.47" | 0" |
| 1993 | 72°F | 53°F | 0" | 0" |
| 1992 | 68°F | 45°F | 0.03" | 0" |
| 1991 | 78°F | 58°F | 0" | 0" |
| 1990 | 72°F | 55°F | 0" | 0" |
| 1989 | 85°F | 56°F | 0" | 0" |
| 1988 | 78°F | 57°F | 0" | 0" |
| 1983 | 74°F | 61°F | 0.13" | 0" |
| 1981 | 63°F | 45°F | 0" | 0" |
| 1980 | 74°F | 58°F | 0" | 0" |
| 1979 | 88°F | 61°F | 1.8" | 0" |
| 1978 | 72°F | 49°F | 0" | 0" |
| 1977 | 72°F | 55°F | 0" | 0" |
| 1976 | 78°F | 55°F | 0" | 0" |
| 1975 | 80°F | 50°F | 0" | 0" |
| 1974 | 75°F | 53°F | 0.1" | 0" |
| 1973 | 78°F | 52°F | 0" | 0" |
| 1972 | 67°F | 54°F | 3.76" | 0" |
| 1971 | 80°F | 52°F | 0.13" | 0" |
July 21 at Nearby Parks
Holiday Weather at Isle Royale
Official NPS WebsiteVisit nps.gov/isro for park information, alerts, and reservations
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