The highest day temperature in December 2023 was 56°F. The lowest night temperature was 21°F. The average values for day and night temperatures during December were 39.7°F и 34.2°F respectivly.

The average sea surface temperature in December 2023 for Portsmouth was 45.6°F. The maximum and minimum values were 42.0°F and 48.8°F respectively.

You can expect various weather conditions during December. Be ready for sunny, cloudy or even gloomy days.

Precipitation total in December for Portsmouth is 1.8 in. It makes december one of the most rainy months of the year.

The average wind speed in December is 9.4 mph. It makes December one of the most windy months of the year for Portsmouth.

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 Portsmouth in December is 4.4 hours.