The highest day temperature in January 2026 was 45°F. The lowest night temperature was 10°F. The average values for day and night temperatures during January were 32.5°F и 30.1°F respectivly.

The average sea surface temperature in January 2026 for Charlestown was 39.0°F. The maximum and minimum values were 36.8°F and 41.8°F respectively.

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

Precipitation total in January for Charlestown is 1.2 in.

The average wind speed in January is 13.3 mph. It makes January the most windy month of the year for Charlestown.

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 Charlestown in January is 5.2 hours.