December weather forecast
Mystic Grove, MA

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Weather in December

The first month of the winter, December, is also an icy month in Mystic Grove, Massachusetts, with temperature in the range of an average low of 25.7°F (-3.5°C) and an average high of 36.5°F (2.5°C).

Temperature

The shift from November to December involves a decrease in the average high-temperature, dropping from a frosty 46.6°F (8.1°C) to an icy 36.5°F (2.5°C). During December, Mystic Grove's temperature averages to a subzero cold 25.7°F (-3.5°C) at night.

Humidity

In December, the average relative humidity is 80%.

Rainfall

In Mystic Grove, in December, it is raining for 9.2 days, with typically 2.72" (69mm) of accumulated precipitation. Throughout the year, there are 147.4 rainfall days, and 29.76" (756mm) of precipitation is accumulated.

Snowfall

January through May, October through December are months with snowfall. In December, it is snowing for 6.9 days. Throughout December, 3.43" (87mm) of snow is accumulated. In Mystic Grove, during the entire year, snow falls for 39.9 days and aggregates up to 23.82" (605mm) of snow.

Daylight

The month with the shortest days is December, with an average of 9h and 12min of daylight.
On the first day of December, sunrise is at 6:57 am and sunset at 4:16 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 4:26 pm EST.

Sunshine

In Mystic Grove, the average sunshine in December is 4.4h.

UV index

The months with the lowest UV index are January through March, October through December, with an average maximum UV index of 2. A UV Index value of 2, and less, symbolizes a minimal health hazard from exposure to the Sun's UV rays for the average person.
Note: The daily maximum UV index of 2 in December interprets into the following advice:
While extended sun exposure does not significantly affect most people, those with sensitive skin, children, and infants should always be protected. It's crucial to reduce time in the direct Sun around mid-day due to the intense solar radiation. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear. Heads up! The UV radiation from the Sun can almost be doubled by snow reflection.

Frequently asked questions

How cold is it in December?

In Mystic Grove, in December, the average high-temperature is 36.5°F (2.5°C), and the average low-temperature is 25.7°F (-3.5°C). In July, the average heat index (a.k.a. 'felt air temperature', 'real feel'), which factors the actual air temperature with the relative humidity, is appraised at 86°F (30°C).

What is the average humidity in December?

In Mystic Grove, Massachusetts, the average relative humidity in December is 80%.

How much does it rain in December?

In December, the rain falls for 9.2 days. Throughout December, 2.72" (69mm) of precipitation is accumulated.

How many days does it snow in December?

In December, it is snowing for 6.9 days. Throughout December, 3.43" (87mm) of snow is accumulated.

What is the month with the shortest days?

With an average of 9h and 12min of daylight, December has the shortest days of the year.

What is the average length of the day in December?

In Mystic Grove, the average day length in December is 9h and 10min.

What time are sunrise and sunset in December?

On the first day of December, sunrise is at 6:57 am and sunset at 4:16 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 4:26 pm EST.

How long on average sun shines in December?

The average sunshine duration in December is 4.4h.

What are the months with the lowest UV index?

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

What is the UV index intensity in December?

In December, the average daily maximum UV index is 2. A UV Index estimate of 2, and below, represents 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
Mystic Grove, MA

Average temperature in December - Mystic Grove, MA
  • Average high temperature in December: 36.5°F

The warmest month (with the highest average high temperature) is July (80.8°F).
The month with the lowest average high temperature is January (30.9°F).

  • Average low temperature in December: 25.7°F

The month with the highest average low temperature is July (61.3°F).
The coldest month (with the lowest average low temperature) is January (18.3°F).

Average pressure in December
Mystic Grove, MA

Average pressure in December - Mystic Grove, 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 (29.93"Hg).

Average wind speed in December
Mystic Grove, MA

Average wind speed in December - Mystic Grove, MA
  • Average wind speed in December: 8.6mph

The windiest month (with the highest average wind speed) is January (9.1mph).
The calmest month (with the lowest average wind speed) is August (5.6mph).

Average humidity in December
Mystic Grove, MA

Average humidity in December - Mystic Grove, MA
  • Average humidity in December: 80%

The month with the highest relative humidity is February (82%).
The month with the lowest relative humidity is April (73%).

Average rainfall in December
Mystic Grove, MA

Average rainfall in December - Mystic Grove, MA
  • Average rainfall in December: 2.72"

The wettest months (with the highest rainfall) are October and November (2.76").
The driest month (with the least rainfall) is September (1.81").

Average rainfall days in December
Mystic Grove, MA

Average rainfall days in December - Mystic Grove, MA
  • Average rainfall days in December: 9.2 days

The month with the highest number of rainy days is May (16.5 days).
The month with the least rainy days is January (6.4 days).

Average snowfall in December
Mystic Grove, MA

Average snowfall in December - Mystic Grove, MA
  • Average snowfall in December: 3.43"

The month with the highest snowfall is February (6.02").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Mystic Grove, MA

Average snowfall days in December - Mystic Grove, MA
  • Average snowfall days in December: 6.9 days

The month with the highest number of snowfall days is January (9.5 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Mystic Grove, MA

Average daylight in December / Average sunshine in December - Mystic Grove, 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 12min).

  • Average sunshine in December: 4h and 2min

The months with the most sunshine are July and August (Average sunshine: 9h and 54min).
The month with the least sunshine is February (Average sunshine: 4h and 18min).

Average sunshine days in December
Mystic Grove, MA

Average sunshine days in December - Mystic Grove, MA
  • Average sunshine days in December: 16.1 days

The month with the most sunshine days is November (17.2 days).
The month with the least sunshine days is April (12.8 days).

Average UV index in December
Mystic Grove, MA

Average UV index in December - Mystic Grove, MA
  • Average UV index in December: 2

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

Average cloud cover in December
Mystic Grove, MA

Average cloud cover in December - Mystic Grove, MA
  • Average cloud cover in December: 51

The month with the most cloud cover is March (Cloud cover 53).
The month with the least cloud cover is August (Cloud cover 38).

Average visibility in December
Mystic Grove, MA

Average visibility in December - Mystic Grove, MA
  • Average visibility in December: 6mi

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

Mystic Grove, Massachusetts, USA

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