Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average snowfall in December
- Average snowfall days in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
December brings a decrease in the average high-temperature, falling from November's chilly 48°F (8.9°C) to a wintry 37.9°F (3.3°C). December nights experience a consistent temperature drop to a subzero cold 27°F (-2.8°C).Humidity
In December, the average relative humidity 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 December, it is snowing for 5.8 days. Throughout December, 4.61" (117mm) of snow is accumulated. In Westford, Massachusetts, 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 December, 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.
Sunshine
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 of 2, and less, symbolizes a low health risk from unprotected exposure to Sun's UV rays for the ordinary person.Note: In December, the maximum UV index of 2 transforms into these recommendations:
Despite most people tolerating extended sun exposure, it is critical to always protect those with sensitive skin, infants, and children. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes. Beware! Reflection from snow can magnify the Sun's UV radiation nearly twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is it in December?
What is the average humidity in December in Westford?
What is the rainiest month?
How much does it rain in December?
How many days does it snow in December?
What is the month with the shortest days?
How many hours of daylight does Westford have in December?
When is the sunrise / sunset in December?
How many hours of sunshine does Westford have in December?
What are the months with the lowest UV index?
What is the UV index reading in December?
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).
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).
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).
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%).
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").
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).
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").
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).
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).
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).
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).
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).
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).
Westford, Massachusetts, USA
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