December weather forecast
Westford, MA

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Weather in December

The first month of the winter, December, is still a cold month in Westford, Massachusetts, with an average temperature ranging between min 27°F (-2.8°C) and max 37.9°F (3.3°C).

Temperature

Westford observes a minor decrease in the average high-temperature with the arrival of December, falling from November's chilly 48°F (8.9°C) to a wintry 37.9°F (3.3°C). Throughout the month of December, Westford observes an average nighttime temperature of 27°F (-2.8°C).

Humidity

The average relative humidity in December in Westford is 77%.

Rainfall

The month with the most rainfall is December, when the rain falls for 10.1 days and typically aggregates up to 2.72" (69mm) of precipitation.

Snowfall

January through May, October through December are months with snowfall. In Westford, in December, snow falls for 5.8 days, with typically accumulated 4.61" (117mm) of snow. In Westford, during the entire year, snow falls for 35.1 days and aggregates up to 24.88" (632mm) of snow.

Daylight

December has the shortest days of the year, with an average of 9h and 6min of daylight.
On the first day of the month, sunrise is at 6:56 am and sunset at 4:13 pm. On the last day of December, in Westford, sunrise is at 7:15 am and sunset at 4:22 pm EST.

Sunshine

In Westford, the average sunshine in December is 4.9h.

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 reading of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV radiation for ordinary individuals.
Note: In December, the average maximum UV index of 2 translates into the following recommendations:
In contrast to children, who must always be shielded from the sun, most people can tolerate up to an hour of sun exposure without any burns. The Sun is at its harshest during midday; protect yourself by staying in shaded areas and minimizing exposure. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat. Be attentive! The reflective property of snow can nearly double the Sun's UV radiation.
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Frequently asked questions

How cold is it in Westford in December?

In December, in Westford, the average high-temperature is 37.9°F (3.3°C), and the average low-temperature is 27°F (-2.8°C). The average heat index (a.k.a. 'apparent temperature', 'feels like'), which takes the relative humidity and factors it into the air temperature reading, in July is calculated to be 87.8°F (31°C).

What is the average humidity in December in Westford?

In December, the average relative humidity in Westford is 77%.

What is the rainiest month in Westford?

The month with the most rainfall in Westford is December, when the rain falls for 10.1 days and typically aggregates up to 2.72" (69mm) of precipitation.

How many days does it rain in December in Westford?

In December, in Westford, Massachusetts, the rain falls for 10.1 days. Throughout December, 2.72" (69mm) of precipitation is accumulated.

How much does it snow in Westford in December?

In December, it is snowing for 5.8 days. Throughout December, 4.61" (117mm) of snow is accumulated.

What is the month with the shortest days in Westford?

December has the shortest days of the year in Westford, Massachusetts, with an average of 9h and 6min of daylight.

How many hours of daylight does Westford have in December?

In Westford, Massachusetts, the average day length in December is 9h and 7min.

When is the sunrise / sunset in December in Westford?

On the first day of December in Westford, Massachusetts, sunrise is at 6:56 am and sunset at 4:13 pm. On the last day of the month, sunrise is at 7:15 am and sunset at 4:22 pm EST.

How long on average sun shines in December in Westford?

The average sunshine duration in December in Westford is 4.9h.

What is the month with the lowest UV index in Westford?

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

What is the UV index reading in December in Westford?

In December, the average daily maximum UV index is 2. A UV Index estimate of 2, and below, represents a low health risk from exposure to the Sun's UV radiation.
Average high temperature
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
Westford, MA

Average temperature in December - Westford, MA
  • Average high temperature in December: 37.9°F

The warmest month (with the highest average high temperature) is July (82.2°F).
The month with the lowest average high temperature is January (32°F).

  • Average low temperature in December: 27°F

The month with the highest average low temperature is July (63.1°F).
The coldest month (with the lowest average low temperature) is January (19.8°F).

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Average pressure in December
Westford, MA

Average pressure in December - Westford, MA
  • Average pressure in December: 30.03"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).

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Average wind speed in December
Westford, MA

Average wind speed in December - Westford, MA
  • Average wind speed in December: 8mph

The windiest month (with the highest average wind speed) is January (8.5mph).
The calmest month (with the lowest average wind speed) is August (5.4mph).

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Average humidity in December
Westford, MA

Average humidity in December - Westford, MA
  • Average humidity in December: 77%

The month with the highest relative humidity is February (80%).
The month with the lowest relative humidity is April (70%).

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Average rainfall in December
Westford, MA

Average rainfall in December - Westford, MA
  • Average rainfall in December: 2.72"

The wettest month (with the highest rainfall) is December (2.72").
The driest month (with the least rainfall) is September (1.46").

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Average rainfall days in December
Westford, MA

Average rainfall days in December - Westford, MA
  • Average rainfall days in December: 10.1 days

The month with the highest number of rainy days is May (15.1 days).
The month with the least rainy days is January (6.6 days).

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Average snowfall in December
Westford, MA

Average snowfall in December - Westford, MA
  • Average snowfall in December: 4.61"

The month with the highest snowfall is February (6.57").
The months with the least snowfall are June, July, August and September (0").

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Average snowfall days in December
Westford, MA

Average snowfall days in December - Westford, MA
  • Average snowfall days in December: 5.8 days

The month with the highest number of snowfall days is February (8.8 days).
The months with the least snowfall days are June, July, August and September (0 days).

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

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

The month with the longest days is June (Average daylight: 15h and 18min).
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 24min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).

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Average sunshine days in December
Westford, MA

Average sunshine days in December - Westford, MA
  • Average sunshine days in December: 16.7 days

The month with the most sunshine days is November (17.8 days).
The month with the least sunshine days is May (13.8 days).

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Average UV index in December
Westford, MA

Average UV index in December - Westford, 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).

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Average cloud cover in December
Westford, MA

Average cloud cover in December - Westford, MA
  • Average cloud cover in December: 46

The month with the most cloud cover is March (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 33).

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Average visibility in December
Westford, MA

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

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

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Westford, Massachusetts, USA

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