December weather forecast
Isle Royale National Park, MI

December witnesses the onset of winter, concluding the cycle of the year. Cold weather characterizes this month, increasing from the cool temperatures of November. Daylight hours are curtailed dramatically, indicating the waning of the Sun. Expected rainfall remains relatively consistent compared to the previous month. The temperature typically fluctuates from 7°F (-13.9°C) to 23°F (-5°C), indicating the reinstatement of the chilling winter.

Temperature

The onset of December coincides with a reduction in the average high-temperature, falling from an icy 35.6°F (2°C) in November to a subzero cold 23°F (-5°C). In the month of December, Isle Royale National Park witnesses a consistent average low-temperature of 6.8°F (-14°C).

Rainfall

In December, in Isle Royale National Park, the rain falls for 11 days. Throughout December, 2.32" (59mm) of precipitation is accumulated. Throughout the year, in Isle Royale National Park, there are 125 rainfall days, and 30.55" (776mm) of precipitation is accumulated.

Ocean temperature

In Isle Royale National Park, in December, the average water temperature is 39.2°F (4°C).
Note: For swimming, this is considered very dangerous and immediately life-threatening. Total loss of breathing control instantly occurs, and clear thinking becomes almost impossible. A specialized swimsuit is obligatory to minimize thermal loss.

Daylight

The month with the shortest days is December, with an average of 8h and 30min of daylight.
On the first day of the month, sunrise is at 8:25 am and sunset at 5:04 pm. On the last day of December, in Isle Royale National Park, Michigan, sunrise is at 8:45 am and sunset at 5:12 pm EST.

Sunshine

November and December, with an average of 3h of sunshine, are months with the least sunshine.

UV index

The months with the lowest UV index in Isle Royale National Park, Michigan, are January, February, November and December, with an average maximum UV index of 1. A UV Index value of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV rays for ordinary individuals.
Note: The maximum UV index of 1 during December leads to these instructions:
Although prolonged sun exposure does not typically bother most people, children, babies, and those with sensitive skin should always have protection. Protect yourself from the midday Sun's peak UV radiation by minimizing exposure. During bright days, sunglasses that offer UVA and UVB defense are recommended.