Isle Royale Weather Forecast
- 4
- 38
Snow Showers
- 11
- 20
Snow Showers Likely
- 6
- 27
Chance Snow Showers
- 11
- 17
Mostly Cloudy
- 22
- 30
Chance Snow Showers
- 13
- 29
Mostly Cloudy
Today 18 Dec Keweenaw
Cloudy. Rain Showers likely with a chance of drizzle in the Morning, then rain and snow Showers in the afternoon. Patchy blowing snow in the afternoon. Snow accumulation up to 1 inch. Windy with Highs in the upper 30s. Temperature falling into the upper 20s in the afternoon. South Winds 10 to 15 Mph with Gusts up to 25 Mph, increasing to north 20 to 30 Mph with Gusts up to 45 Mph in the afternoon. Chance of precipitation 90 percent.
Tonight 18 Dec Keweenaw
Very windy. Snow Showers. Blowing snow and heavy freezing spray. Snow may be heavy at Times in the evening. Visibility one quarter mile or less at Times. Snow accumulation of 4 to 6 Inches. Lows around 4 above inland to around 10 above at the shore. North Winds 30 to 40 Mph. Chance of snow 100 percent.
Isle Royale Temperature Statistics
December Temperature
Copper Harbor (58.4 miles)
Lowest 13 December, 2025
6.1 °FAverage December
19.5 °FHighest 11 December, 2025
30 °F
Climate (2020–Present)
Copper Harbor (58.4 miles)
Average Low 2020–2025
38.7 °FAverage 2020–2025
44.9 °FAverage High 2020–2025
51.1 °F