Hyannis (Cape Cod) weather in December

December in Hyannis: cold, rainy, with clean air — one of the weakest months to visit.

Updated September 2026 · climate normals from ERA5 reanalysis

Hyannis🇺🇸 United States · Northeast & Atlantic Canada · Beach38
  1. 35Jan
  2. 43Feb
  3. 50Mar
  4. 61Apr
  5. 72May
  6. 81Jun
  7. 91Jul
  8. 88Aug
  9. 78Sep
  10. 62Oct
  11. 54Nov
  12. 38Dec

#11 of 12 months in Hyannis · #1304 of 1413 destinations to visit in December · comfort 38/100 (tier F)

Days
7°C
Nights
-1°C
Wet days
11
Sun
5.4 h
Humidity
72%
Daylight
9 h
Hyannis, United States
Photo: Rcsprinter123 · CC BY 3.0

Traveller notes on Hyannis in December

Other months in Hyannis

Cape Cod's own forum doesn't sugarcoat February: expect a real chance of high wind, biting cold and snow, and New England weather here is notoriously hard to predict from one day to the next. Multiple posters recommended layering with fleece under a windproof shell so you can still get outside comfortably. A good number of shops and restaurants that cater to the summer crowd simply close for the season, so plan meals ahead rather than expecting to wander and find something open. It's a legitimate visit for solitude and off-season prices, just not the postcard version of the Cape.
CapeCodWinterRegular · February · 1 month ago · Read more on Tripadvisor ↗
Forum posters describe August as typically the warmest month, often in the 80s-90sF and humid, though the Cape's ocean breezes keep it noticeably cooler than inland Massachusetts at the same time - a stretch of 90F+ days is possible, but so is a cooler, rawer spell within the same month. Posters call August rain genuinely unpredictable, ranging from a light sprinkle to a full washed-out day, though it's typically the lowest-rain month of the summer overall. Mosquitoes are a real, near-constant presence, especially in the evenings, with repellent treated as standard packing. Posters consistently name the last two weeks of August through September as the more reliably pleasant stretch compared to June or early August.
Tripadvisor community · August · 1 month ago · Read more on Tripadvisor ↗

Add your own note from Hyannis's card on the map.

Hyannis climate normals — December

Daytime high7°C / 44°F🧥 cold
Nighttime low-1°C / 30°F
Feels like (high)3°C / 37°F
Sea temperature6°C / 43°F🥶 cold sea
Rainfall118 mm / 4.6 in🌧 rainy
Rainy days11 days
Humidity72%💧 humid
Dew point-1°C / 30°F
Sunshine5.4 h/day
Daylight9.2 h
Wind28 km/h / 18 mph
Snowfall4.9 cm / 1.9 in
Air quality (US AQI)33🍃 good

Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.

Crowds in Hyannis in December

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.

BusyWinter / Christmas break in United States, school holidays in 2 of the markets that fill it(estimated)

JFMAMJJASOND

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).

Toughest weatherHyannis's weather peaks June–August, best around July.

JFMAMJJASOND

Best weatherFair weatherToughest weather

What's on in Hyannis in December

Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.

  • Season

    Winter shutdown

    1 Nov – 15 AprOff-season shutdownClosures

    Most of the seasonal restaurants and shops close and the ferry drops to the winter timetable, though Hyannis keeps more open year-round than the rest of the Cape because people actually live here. Rates halve.

What's on around the world in December →

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?

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Hyannis in December — FAQ

Is December a good time to visit Hyannis?
December in Hyannis: cold, rainy, with clean air — one of the weakest months to visit. It ranks #11 of 12 months for Hyannis on SeasonMap's comfort score (38/100).
What is the weather like in Hyannis in December?
In December, Hyannis averages a daily high of 6.9°C and a low of -1.2°C, with about 118 mm of rain over roughly 10.6 rainy days.
What is the air quality in Hyannis in December?
Hyannis has a mean US Air Quality Index of about 33 in December.
Does it snow in Hyannis in December?
Hyannis sees roughly 4.9 cm of snowfall in December.

Within 300 km: Nantucket's Christmas Stroll around 27 Nov – 8 Dec, and Boston's First Night on 31 Dec – 1 Jan.