SeasonMapHyannis (Cape Cod) weather in July
United States
July in Hyannis: warm, a little rain, with muggy air — one of the best months to visit.
#2 of 12 months in Hyannis · #329 of 1383 destinations to visit in July · comfort 88/100 (tier A)
Updated September 2026 · climate normals from ERA5 reanalysis
Traveller notes on Hyannis in July
Notes from nearby Nantucket (44 km away)
Hyannis doesn't have its own notes for July yet — these are about Nantucket, close enough to share the season.
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 Hyannis's card on the map.
Hyannis climate normals — July
| Daytime high | 25°C / 76°F | 🌤 warm |
|---|---|---|
| Nighttime low | 21°C / 69°F | |
| Sea temperature | 25°C / 78°F | 😎 warm sea |
| Rainfall | 77 mm / 3 in | 🌦 some rain |
| Rainy days | 8 days | |
| Humidity | 83% | 💦 very humid |
| Dew point | 20°C / 67°F | |
| Sunshine | 11.6 h/day | |
| Daylight | 14.8 h | |
| Wind | 22 km/h / 14 mph | |
| Air quality (US AQI) | 64 | 🙂 moderate |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Hyannis 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 crowdsIsland ferry high season, Peak summer season, Summer break in United States(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Hyannis'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 weatherHyannis's weather peaks July–September, best around August.
July includes White shark season.
Best weatherFair weatherToughest weather
What's on in Hyannis in July
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Opening
Island ferry high season
20 May – 15 Oct · usuallySummer season opensCrowdedBook earlyHyannis is the mainland end of the Nantucket boats, and the summer timetable adds fast ferries and extra sailings from late May. Car spaces on the traditional boat are released months ahead and go the day they open. Source ↗
- Nature
White shark season
1 Jun – 31 Oct · usuallyWildlife seasonRiskWhite sharks follow the grey seals into Cape waters from early summer and are gone by late autumn, with the tagged detections peaking in August and September. It is the ocean side that closes for sightings, not the calmer Nantucket Sound beaches in town. Source ↗
- Season
Peak summer season
1 Jul – 31 AugSchool holidaysCrowdedBook earlyThe whole Cape funnels through here for the boats, and Route 6 and the rotaries jam every Friday afternoon and Sunday evening. Main Street is at its best on a weekday morning before the day-boats land.
Nearby, and something's on
Within 300 km of Hyannis — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Hyannis?
Hyannis in July — FAQ
- Is July a good time to visit Hyannis?
- July in Hyannis: warm, a little rain, with muggy air — one of the best months to visit. It ranks #2 of 12 months for Hyannis on SeasonMap's comfort score (88/100).
- What is the weather like in Hyannis in July?
- In July, Hyannis averages a daily high of 24.5°C and a low of 20.8°C, with about 76.5 mm of rain over roughly 8.2 rainy days.
- What is the air quality in Hyannis in July?
- Hyannis has a mean US Air Quality Index of about 64 in July.
Other months in Hyannis
Compare Hyannis in July
Warmer or cooler than Hyannis 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.