The highest day temperature in July 2026 was 79°F. The lowest night temperature was 65°F. The average values for day and night temperatures during July were 74.6°F и 70.1°F respectivly.

The average sea surface temperature in July 2026 for Charlestown was 70.6°F. The maximum and minimum values were 68.2°F and 72.6°F respectively.

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

Precipitation total in July for Charlestown is 0.9 in. It makes july one of the least rainy months of the year.

The average wind speed in July is 9.3 mph. It makes July one of the most windless months 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 July is 8.5 hours.