The highest day temperature in December 2025 was 34°F. The lowest night temperature was -12°F. The average values for day and night temperatures during December were 16.3°F и 11.5°F respectivly.

The average sea surface temperature in December 2025 for Grand Marais was 37.0°F. The maximum and minimum values were 34.8°F and 39.2°F respectively.

Most of the days in December are gloomy but you can also expect sunny days.

Precipitation total in December for Grand Marais is 0.6 in. It makes december one of the least rainy months of the year.

The average wind speed in December is 9.9 mph. It makes December one of the most windy months of the year for Grand Marais.

We are using day length and cloud cover information for each day of the month to calculate averages for this chart. Average sunny hours for Grand Marais in December is 3.3 hours.