The highest day temperature in March 2025 was 56°F. The lowest night temperature was 5°F. The average values for day and night temperatures during March were 42.9°F и 29.8°F respectivly.

The average sea surface temperature in March 2025 for Portsmouth was 37.0°F. The maximum and minimum values were 35.2°F and 38.8°F respectively.

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

Precipitation total in March for Portsmouth is 1.2 in.

The average wind speed in March is 9.7 mph. It makes March the most windy month 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 March is 5.9 hours.