Nantucket weather in July
Temperature, sea and sunshine in July: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in July
Fair
Best time to visit: July – August
What is the weather like in Nantucket in July?
In July, Nantucket is mild: daytime highs average 20 °C, and nights cool down to about 19 °C. The sea averages 19.2 °C – bracing, so a wetsuit helps for longer swims. The sun shines for around 9 hours a day. Rain falls on about 8 days, adding up to 77 mm. The air is often humid and muggy. All in all, July is a so-so month for a holiday in Nantucket.
July compared
How the weather changes from June to August. Tap a month to open it.
More details for July
- Daylight
- 14 h 54 min05:19 – 20:13
- UV index
- 9 · very highclear sky, noon (estimate)All months
- Muggy days
- 15 daysdew point 18 °C or moreAll months
- Wind
- 28 km/haverage daily peakAll months
- Cloud cover
- 54 %on averageAll months
- Hot days
- 0 days30 °C or moreAll months
- Snow days
- 0 days1 cm or more of fresh snowAll months
- Time zone
- UTC−4America/New_York
How the score comes together
- Temperatureweight 35 %20 %
- Seaweight 25 %31 %
- Sunshineweight 20 %93 %
- Few rainy daysweight 20 %70 %
Each factor is rated from 0 to 100 % and weighted for the travel style “Sun, sea & sand”.
What to pack in July
- Wetsuit for longer swims
- Sunscreen
- Sunglasses & sun hat
- Insect repellent
- Rain jacket or umbrella
Nantucket in July: quick answers
Is Nantucket hot in July?
No. In July, Nantucket is mild: daytime highs average 20 °C and nights drop to about 19 °C.
Can you swim in Nantucket in July?
Only if you don't mind cold water: in July the sea averages just 19.2 °C. Comfortable swimming is possible in August.
Does it rain much in Nantucket in July?
Rain falls on about 8 days, adding up to 77 mm.
Nantucket month by month
The whole year in NantucketAll destinations: USAWhere to go in JulySea temperature in July
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences