Trondheim is typically cool in December.

Maximum temperatures go down compared to the previous month from +4°C to +1°C. The minimum temperature also goes down from -1°C to -4°C.

Pack a sweater and a jacket as there will be cooler temperatures.

December is one of the coolest months in Trondheim, here is the comparison with other months:

Water in Trondheim in December is Cold. It varies from +5°C to +9°C, with an average of +7°C. Note that the air temperature is lower than the water temperature, averaging around +1°C.

In December, water temperatures are average relative to the rest of the year:

December weather is still as ok as in November. It’s getting colder in December. From +4°C in the day, the average maximum temperature lowers to +1°C. As December arrives, the amount of rainfall goes down. On average, the rainfall volume decreases from 63 mm to 60 mm. Humidity levels don’t change as the month goes on, averaging around 80%. The average wind speed doesn’t change much during December, staying around 2 m/s. The amount of sunny days stay about the same, averaging 2 sunny days during the month.

January brings much the same weather, it remains ok.

December is one of the snowiest months in Trondheim.

Here’s how December is compared with other months in the amount of snow, total mm:

The climate in Trondheim in December has not changed much over the last 43 years.

The average temperature was the lowest in 1981 (+7°C) and the highest in 2014 (+11°C). The driest year was 2002 with only 617 mm of rainfall, and the wettest year was 2024 with 1410 mm.

For this page, we’ve looked at the typical weather in Trondheim, based on historical hourly weather data from January 1, 1979, to December 31, 2023.

For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.