Boston weather in December
Temperature, sea and sunshine in December: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in December
Poor
Best time to visit: May – September
What is the weather like in Boston in December?
In December, Boston is cold: daytime highs average 5 °C, and nights often drop below freezing (−1 °C). The sea averages 7.7 °C – swimming is only for the hardy. Expect around 4 hours of sunshine a day. Rain is frequent, with about 11 rainy days and 113 mm in total. Snow falls on about 3 days. All in all, December is not an ideal month for a holiday in Boston.
December compared
How the weather changes from November to January. Tap a month to open it.
| NovemberNov | DecemberDec | JanuaryJan | |
|---|---|---|---|
| Score | 35 | 18 | 22 |
| Day | 10° | 5° | 2° |
| Night | 4° | −1° | −5° |
| Sea | 10° | 8° | 5° |
| Sun | 5 h | 4 h | 5 h |
| Rain days | 9 | 11 | 10 |
More details for December
- Daylight
- 9 h 6 min07:06 – 16:13
- UV index
- 1 · lowclear sky, noon (estimate)All months
- Muggy days
- 0 daysdew point 18 °C or moreAll months
- Wind
- 23 km/haverage daily peakAll months
- Cloud cover
- 58 %on averageAll months
- Hot days
- 0 days30 °C or moreAll months
- Snow days
- 3 days1 cm or more of fresh snowAll months
- Time zone
- UTC−5America/New_York
How the score comes together
- Temperatureweight 50 %0 %
- Sunshineweight 20 %17 %
- Few rainy daysweight 30 %49 %
Each factor is rated from 0 to 100 % and weighted for the travel style “City break”.
What to pack in December
- Warm jacket
- Hat, scarf & gloves
- Rain jacket or umbrella
Boston in December: quick answers
Is Boston hot in December?
No. In December, Boston is cold: daytime highs average 5 °C and nights drop to about −1 °C.
Can you swim in Boston in December?
Only if you don't mind cold water: in December the sea averages just 7.7 °C. Comfortable swimming temperatures are not reached at any time of year.
Does it rain much in Boston in December?
Rain is frequent, with about 11 rainy days and 113 mm in total.
Boston month by month
The whole year in BostonAll destinations: USAWhere to go in DecemberSea temperature in December
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