December weather forecast
Boylston, MA

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Weather in December

The first month of the winter, December, is also an icy month in Boylston, Massachusetts, with an average temperature fluctuating between 26.6°F (-3°C) and 37.4°F (3°C).

Temperature

Boylston in December demonstrates a small temperature transition, adjusting from an average high of a chilly 47.3°F (8.5°C) in November to a wintry 37.4°F (3°C). Throughout the month of December, the nighttime temperature dips to an average of 26.6°F (-3°C).

Humidity

The average relative humidity in December in Boylston is 78%.

Rainfall

December is the month with the most rainfall in Boylston. Rain falls for 10.7 days and accumulates 2.91" (74mm) of precipitation.

Snowfall

January through May, October through December are months with snowfall. In Boylston, during December, snow falls for 5.6 days and regularly aggregates up to 4.33" (110mm) of snow. Throughout the year, there are 36.5 snowfall days, and 23.82" (605mm) of snow is accumulated.

Daylight

December has the shortest days of the year, with an average of 9h and 6min of daylight.
On the first day of December in Boylston, sunrise is at 6:57 am and sunset at 4:15 pm. On the last day of the month, sunrise is at 7:15 am and sunset at 4:24 pm EST.

Sunshine

In Boylston, the average sunshine in December is 4.8h.

UV index

January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index value of 2, and less, symbolizes a low health risk from exposure to the Sun's UV radiation for the average person.
Note: In December, the average maximum UV index of 2 translates into the following recommendations:
While extended sun exposure does not significantly affect most people, those with sensitive skin, children, and infants should always be protected. The Sun's UV radiation is especially harmful around midday, so reduce exposure and stay safe. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun. Be informed! The Sun's UV radiation can be nearly doubled due to the reflection from snow.

Frequently asked questions

How cold is December?

In December, the average high-temperature and low-temperature are 37.4°F (3°C) and 26.6°F (-3°C) respectively. In July, the average heat index (a.k.a. 'feels like', 'felt air temperature'), which factors the actual air temperature with the relative humidity, is appraised at 87.8°F (31°C).

What is the average humidity in December?

In Boylston, the average relative humidity in December is 78%.

What is the wettest month?

The month with the most rainfall is December, when the rain falls for 10.7 days and typically aggregates up to 2.91" (74mm) of precipitation.

How many days does it rain in December?

In December, the rain falls for 10.7 days. Throughout December, 2.91" (74mm) of precipitation is accumulated.

How much does it snow in December?

In Boylston, in December, during 5.6 snowfall days, 4.33" (110mm) of snow is typically accumulated.

What is the month with the shortest days?

The month with the shortest days is December, with an average of 9h and 6min of daylight.

How many hours of daylight does Boylston have in December?

The average day length in December is 9h and 8min.

When are sunrise and sunset in December?

On the first day of December in Boylston, sunrise is at 6:57 am and sunset at 4:15 pm. On the last day of the month, sunrise is at 7:15 am and sunset at 4:24 pm EST.

How many hours of sunshine does Boylston have in December?

In Boylston, the average sunshine duration in December is 4.8h.

What is the month with the lowest UV index?

January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index.

How high is the UV index in December?

In December, the average daily maximum UV index is 2. A UV Index value of 2, and less, symbolizes a minimal hazard to health from unprotected exposure to UV radiation.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Boylston, MA

Average temperature in December - Boylston, MA
  • Average high temperature in December: 37.4°F

The warmest month (with the highest average high temperature) is July (81.9°F).
The month with the lowest average high temperature is January (31.5°F).

  • Average low temperature in December: 26.6°F

The month with the highest average low temperature is July (62.2°F).
The coldest month (with the lowest average low temperature) is January (19.8°F).

Average pressure in December
Boylston, MA

Average pressure in December - Boylston, MA
  • Average pressure in December: 30.04"Hg

The month with the highest atmospheric pressure is November (30.07"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

Average wind speed in December
Boylston, MA

Average wind speed in December - Boylston, MA
  • Average wind speed in December: 8.2mph

The windiest month (with the highest average wind speed) is January (8.6mph).
The calmest month (with the lowest average wind speed) is August (5.5mph).

Average humidity in December
Boylston, MA

Average humidity in December - Boylston, MA
  • Average humidity in December: 78%

The month with the highest relative humidity is February (81%).
The month with the lowest relative humidity is April (71%).

Average rainfall in December
Boylston, MA

Average rainfall in December - Boylston, MA
  • Average rainfall in December: 2.91"

The wettest month (with the highest rainfall) is December (2.91").
The driest month (with the least rainfall) is September (1.57").

Average rainfall days in December
Boylston, MA

Average rainfall days in December - Boylston, MA
  • Average rainfall days in December: 10.7 days

The month with the highest number of rainy days is July (16 days).
The month with the least rainy days is February (7.3 days).

Average snowfall in December
Boylston, MA

Average snowfall in December - Boylston, MA
  • Average snowfall in December: 4.33"

The month with the highest snowfall is February (6.1").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Boylston, MA

Average snowfall days in December - Boylston, MA
  • Average snowfall days in December: 5.6 days

The month with the highest number of snowfall days is February (9.4 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Boylston, MA

Average daylight in December / Average sunshine in December - Boylston, MA
  • Average daylight in December: 9h and 1min

The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 6min).

  • Average sunshine in December: 4h and 5min

The month with the most sunshine is August (Average sunshine: 10h and 12min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).

Average sunshine days in December
Boylston, MA

Average sunshine days in December - Boylston, MA
  • Average sunshine days in December: 16.5 days

The month with the most sunshine days is November (17.4 days).
The month with the least sunshine days is July (12.8 days).

Average UV index in December
Boylston, MA

Average UV index in December - Boylston, MA
  • Average UV index in December: 2

The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).

Average cloud cover in December
Boylston, MA

Average cloud cover in December - Boylston, MA
  • Average cloud cover in December: 47

The month with the most cloud cover is March (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 34).

Average visibility in December
Boylston, MA

Average visibility in December - Boylston, MA
  • Average visibility in December: 6mi

The months with the highest visibility are March, April, October, November and December (6mi).
The months with the lowest visibility are January, February, May, June, July, August and September (5mi).

Boylston, Massachusetts, USA

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