The highest day temperature in August 2025 was 89°F. The lowest night temperature was 59°F. The average values for day and night temperatures during August were 78.8°F и 65.9°F respectivly.

The average sea surface temperature in August 2025 for Mystic was 71.9°F. The maximum and minimum values were 69.8°F and 76.2°F respectively.

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

Precipitation total in August for Mystic is 1.0 in. It makes august one of the least rainy months of the year.

The average wind speed in August is 7.2 mph. It makes August the most windless month of the year for Mystic.

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 Mystic in August is 7.9 hours.