The highest day temperature in December 2025 was 44°F. The lowest night temperature was 24°F. The average values for day and night temperatures during December were 33.6°F и 32.4°F respectivly.

The average sea surface temperature in December 2025 for Trondheim was 42.4°F. The maximum and minimum values were 39.2°F and 45.2°F respectively.

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

Precipitation total in December for Trondheim is 2.6 in.

The average wind speed in December is 8.0 mph. This value is relatively stable throughout the year.

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 Trondheim in December is 1.8 hours.