SeasonMapNantucket weather in July
United States
July in Nantucket: warm, a little rain, with muggy air — one of the best months to visit.
#2 of 12 months in Nantucket · #485 of 1383 destinations to visit in July · comfort 85/100 (tier A)
Updated September 2026 · climate normals from ERA5 reanalysis
Traveller notes on Nantucket in July
Nantucket's forum rates July for warm, sunny days, with one recurring caveat worth knowing before booking a beach-heavy trip: the ocean itself stays genuinely chilly until August catches up, so swimming is more bracing than the air temperature would suggest. Regulars who want both warm water and warm air tend to point toward September instead.
Add your own note from Nantucket's card on the map.
Nantucket climate normals — July
| Daytime high | 25°C / 76°F | 🌤 warm |
|---|---|---|
| Nighttime low | 18°C / 64°F | |
| Feels like (high) | 26°C / 79°F | |
| Sea temperature | 20°C / 68°F | 🌊 fresh |
| Rainfall | 52 mm / 2 in | 🌦 some rain |
| Rainy days | 4 days | |
| Humidity | 91% | 💦 very humid |
| Dew point | 19°C / 66°F | |
| Sunshine | 11.6 h/day | |
| Daylight | 14.8 h | |
| Wind | 27 km/h / 17 mph | |
| Air quality (US AQI) | 63 | 🙂 moderate |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Nantucket in July
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
Peak crowdsNantucket Film Festival, High summer, Summer break in United States(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Nantucket's weather
Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).
Best weatherNantucket's weather peaks June–August.
July includes Nantucket Film Festival.
Best weatherFair weatherToughest weather
What's on in Nantucket in July
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Hazard
Tick season
1 Apr – 31 Oct · usuallyInsect seasonThe island's deer ticks carry Lyme, babesiosis and tularemia at rates among the highest anywhere, and the moors and bike-path verges are where they wait. Long trousers, and a check at the end of every day. Source ↗
- Season
Fog season
1 May – 31 Jul · usuallyRiskClosuresWarm air over a cold sea puts the island inside cloud for days at a stretch in early summer, and the small planes to Boston and Hyannis are the first thing it stops. Build a spare day into a June trip. Source ↗
- Festival
Nantucket Film Festival
20 Jun – 1 Jul · usuallyCrowdedBook earlyFive days at the end of June built around screenwriting rather than red carpets, with staged readings and panels in the old whaling-town halls. Rooms are already at summer rates by then. Source ↗
- Season
High summer
1 Jul – 31 AugSchool holidaysCrowdedBook earlyPopulation multiplies by five, the car ferry is booked out months ahead and dinner needs a reservation two weeks early. Bring a bike instead of a car and the island works. Source ↗
- Season
Sea warm enough to swim
15 Jul – 20 Sep · usuallyThe island sits far enough offshore that the water lags the air by a month. The harbour beaches on the sound side are always several degrees warmer than the south shore. Source ↗
Nearby, and something's on
Within 300 km of Nantucket — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Nantucket?
Nantucket in July — FAQ
- Is July a good time to visit Nantucket?
- July in Nantucket: warm, a little rain, with muggy air — one of the best months to visit. It ranks #2 of 12 months for Nantucket on SeasonMap's comfort score (85/100).
- What is the weather like in Nantucket in July?
- In July, Nantucket averages a daily high of 24.6°C and a low of 17.9°C, with about 51.5 mm of rain over roughly 4.2 rainy days.
- What is the air quality in Nantucket in July?
- Nantucket has a mean US Air Quality Index of about 63 in July.
Other months in Nantucket
Compare Nantucket in July
Warmer or cooler than Nantucket in July
Similar destinations in North America — July
Within 300 km: Newport's Newport Folk Festival on 24–26 Jul, and Boston's Whales on Stellwagen Bank around 15 Apr – 20 Oct.