December weather forecast
Dedham, MA

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Weather in December

December, the first month of the winter in Dedham, is also a wintry month, with an average temperature varying between 29.1°F (-1.6°C) and 39.6°F (4.2°C).

Temperature

December shows a mild decline in the average high-temperature, falling from November's chilly 49.3°F (9.6°C) to an icy 39.6°F (4.2°C). The average nighttime temperature in Dedham lowers to a freezing cold 29.1°F (-1.6°C) throughout December.

Humidity

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

Rainfall

The month with the most rainfall is December, when the rain falls for 10.7 days and typically aggregates up to 2.95" (75mm) of precipitation.

Snowfall

Months with snowfall in Dedham are January through April, October through December. In Dedham, in December, during 5.8 snowfall days, 4.21" (107mm) of snow is typically accumulated. In Dedham, during the entire year, snow falls for 32.7 days and aggregates up to 22.01" (559mm) of snow.

Daylight

December has the shortest days of the year, with an average of 9h and 12min of daylight.
On the first day of December, sunrise is at 6:54 am and sunset at 4:13 pm. On the last day of the month, sunrise is at 7:13 am and sunset at 4:22 pm EST.

Sunshine

In December, the average sunshine is 4.9h.

UV index

The months with the lowest UV index are January through March, November and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents 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:
Those with sensitive skin, infants, and children require constant safeguarding from prolonged sun exposure. Considering the Sun's intensity during midday, it's wise to minimize direct exposure. Arm yourself against UV rays' harm with protective apparel and UV-filtering shades. Be prepared! The intensity of the Sun's UV radiation can be amplified nearly double due to snow reflection.

Frequently asked questions

Is it cold during December?

An average high-temperature, in December, in Dedham, is 39.6°F (4.2°C) and the average low-temperature is 29.1°F (-1.6°C). The average heat index (a.k.a. 'apparent temperature', 'feels like'), which factors the actual air temperature with the relative humidity, in July is calculated to be 86°F (30°C).

What is the average humidity in December?

In December, the average relative humidity is 77%.

What is the rainiest month?

The month with the most rainfall is December, when the rain falls for 10.7 days and typically aggregates up to 2.95" (75mm) of precipitation.

How many days does it rain in December?

In Dedham, in December, during 10.7 rainfall days, 2.95" (75mm) of precipitation is typically accumulated.

How many days does it snow in December?

In Dedham, in December, during 5.8 snowfall days, 4.21" (107mm) 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 12min of daylight.

How many hours of daylight does Dedham have in December?

In Dedham, the average day length in December is 9h and 9min.

When is the sunrise / sunset in December?

In December, on the first day of the month, sunrise is at 6:54 am and sunset at 4:13 pm. On the last day of the month, sunrise is at 7:13 am and sunset at 4:22 pm EST.

How long on average sun shines in December?

In Dedham, the average sunshine duration in December is 4.9h.

When is 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.

What is the UV index intensity in December?

In Dedham, the average daily maximum UV index in December is 2. A UV Index estimate of 2, and below, represents a low health risk from exposure to Sun's UV rays.
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
Dedham, MA

Average temperature in December - Dedham, MA
  • Average high temperature in December: 39.6°F

The warmest month (with the highest average high temperature) is July (81.3°F).
The month with the lowest average high temperature is January (33.6°F).

  • Average low temperature in December: 29.1°F

The month with the highest average low temperature is July (64.8°F).
The coldest month (with the lowest average low temperature) is January (21.9°F).

Average pressure in December
Dedham, MA

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

Average wind speed in December
Dedham, MA

Average wind speed in December - Dedham, MA
  • Average wind speed in December: 8.9mph

The windiest month (with the highest average wind speed) is January (9.5mph).
The calmest month (with the lowest average wind speed) is August (6mph).

Average humidity in December
Dedham, MA

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

The month with the highest relative humidity is February (78%).
The month with the lowest relative humidity is April (70%).

Average rainfall in December
Dedham, MA

Average rainfall in December - Dedham, MA
  • Average rainfall in December: 2.95"

The wettest month (with the highest rainfall) is December (2.95").
The driest month (with the least rainfall) is September (1.5").

Average rainfall days in December
Dedham, MA

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

The month with the highest number of rainy days is July (15.8 days).
The months with the least rainy days are January and February (7.8 days).

Average snowfall in December
Dedham, MA

Average snowfall in December - Dedham, MA
  • Average snowfall in December: 4.21"

The month with the highest snowfall is March (5.24").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in December
Dedham, MA

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

The month with the highest number of snowfall days is February (8.2 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

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

Average daylight in December / Average sunshine in December - Dedham, 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 5min

The month with the most sunshine is August (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).

Average sunshine days in December
Dedham, MA

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

The month with the most sunshine days is November (18 days).
The month with the least sunshine days is April (13.2 days).

Average UV index in December
Dedham, MA

Average UV index in December - Dedham, 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
Dedham, MA

Average cloud cover in December - Dedham, 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 33).

Average visibility in December
Dedham, MA

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

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

Dedham, Massachusetts, USA

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