The highest day temperature in December 2025 was 45°F. The lowest night temperature was 16°F. The average values for day and night temperatures during December were 30.5°F и 29.1°F respectivly.

The average sea surface temperature in December 2025 for St. John's was 36.3°F. The maximum and minimum values were 33.8°F and 40.6°F respectively.

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

Precipitation total in December for St. John's is 1.9 in.

The average wind speed in December is 15.3 mph. It makes December one of the most windy months of the year for St. John's.

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 St. John's in December is 2.3 hours.