The highest day temperature in January 2026 was 54°F. The lowest night temperature was -8°F. The average values for day and night temperatures during January were 30.3°F и 20.5°F respectivly.

The average sea surface temperature in January 2026 for Plymouth was 36.0°F. The maximum and minimum values were 31.4°F and 39.2°F respectively.

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

Precipitation total in January for Plymouth is 1.2 in. It makes january one of the most rainy months of the year.

The average wind speed in January is 10.7 mph. It makes January one of the most windy months of the year for Plymouth.

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 Plymouth in January is 5.0 hours.