The highest day temperature in July 2025 was 82°F. The lowest night temperature was 67°F. The average values for day and night temperatures during July were 77.3°F и 72.1°F respectivly.

The average sea surface temperature in July 2025 for Martha's Vineyard was 70.2°F. The maximum and minimum values were 66.0°F and 73.4°F respectively.

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

Precipitation total in July for Martha's Vineyard is 1.1 in.

The average wind speed in July is 10.3 mph. It makes July the most windless month of the year for Martha's Vineyard.

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 Martha's Vineyard in July is 8.1 hours.