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 involves a decrease in temperature, down from a frosty 48.2°F (9°C) in November to a wintry 37.9°F (3.3°C). An average minimum temperature of 27.3°F (-2.6°C) marks the month of December.Humidity
In December, the average relative humidity in Chelmsford is 77%.Rainfall
The month with the most rainfall in Chelmsford is December, when the rain falls for 10.9 days and typically aggregates up to 2.87" (73mm) of precipitation.Snowfall
January through May, October through December are months with snowfall in Chelmsford. In Chelmsford, Massachusetts, during December, snow falls for 5.6 days and regularly aggregates up to 4.41" (112mm) of snow. Throughout the year, there are 32.6 snowfall days, and 21.61" (549mm) 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 the month, sunrise is at 6:56 am and sunset at 4:13 pm. On the last day of December, sunrise is at 7:15 am and sunset at 4:22 pm EST.
Sunshine
In Chelmsford, the average sunshine in December is 4.9h.UV index
The months with the lowest UV index in Chelmsford, Massachusetts, are January through March, November and December, with an average maximum UV index of 2. A UV Index value of 2, and less, symbolizes a minimal health vulnerability from unprotected exposure to Sun's UV rays for ordinary individuals.Note: The daily high UV index of 2 during December translates into the following recommendations:
Though the majority can handle prolonged sun exposure, it is crucial to always shield babies, children, and those with fair skin. For skin protection, it's recommended to minimize Sun exposure during its peak hours around midday. A hat with a broad brim is indispensable, filtering out up to half of UV rays. Take careful note! The UV radiation of the Sun can be nearly doubled by snow reflection.
Frequently asked questions
Is December cold in Chelmsford?
What is the average humidity in December in Chelmsford?
What is the rainiest month in Chelmsford?
How many days does it rain in December in Chelmsford?
How much does it snow in Chelmsford in December?
What is the month with the shortest days in Chelmsford?
How many hours of daylight does Chelmsford have in December?
When are sunrise and sunset in December in Chelmsford?
How many hours of sunshine does Chelmsford have in December?
What are the months with the lowest UV index in Chelmsford?
What is the UV index intensity in December in Chelmsford?
Average temperature in December
Chelmsford, 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 (32.5°F).
- Average low temperature in December: 27.3°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 (19.9°F).
Average pressure in December
Chelmsford, 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
Chelmsford, MA
- Average wind speed in December: 8.3mph
The windiest month (with the highest average wind speed) is January (8.8mph).
The calmest months (with the lowest average wind speed) are July and August (5.5mph).
Average humidity in December
Chelmsford, 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
Chelmsford, MA
- Average rainfall in December: 2.87"
The wettest month (with the highest rainfall) is December (2.87").
The driest month (with the least rainfall) is September (1.46").
Average rainfall days in December
Chelmsford, MA
- Average rainfall days in December: 10.9 days
The month with the highest number of rainy days is May (15.6 days).
The month with the least rainy days is February (6.9 days).
Average snowfall in December
Chelmsford, MA
- Average snowfall in December: 4.41"
The month with the highest snowfall is February (5.98").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Chelmsford, MA
- Average snowfall days in December: 5.6 days
The month with the highest number of snowfall days is February (8.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Chelmsford, 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 36min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).
Average sunshine days in December
Chelmsford, MA
- Average sunshine days in December: 16.6 days
The month with the most sunshine days is November (17.4 days).
The month with the least sunshine days is May (13.6 days).
Average UV index in December
Chelmsford, 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
Chelmsford, MA
- Average cloud cover in December: 46
The month with the most cloud cover is March (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 31).
Average visibility in December
Chelmsford, MA
- Average visibility in December: 6mi
The months with the highest visibility are January, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is February (5mi).
Chelmsford, Massachusetts, USA
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