December weather forecast
Swansea, MA

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Weather in December

The first month of the winter, December, is also a wintry month in Swansea, Massachusetts, with temperature in the range of an average low of 31.8°F (-0.1°C) and an average high of 42.1°F (5.6°C).

Temperature

Swansea in December experiences a gentle temperature dip, with average high-temperatures reducing from a fresh 50.9°F (10.5°C) in November to a cold 42.1°F (5.6°C). The average low-temperature of 31.8°F (-0.1°C) is witnessed during December.

Humidity

In December, the average relative humidity is 76%.

Rainfall

In Swansea, during December, the rain falls for 9.6 days and regularly aggregates up to 1.73" (44mm) of precipitation. In Swansea, Massachusetts, during the entire year, the rain falls for 135.4 days and collects up to 18.31" (465mm) of precipitation.

Snowfall

January through May, November and December are months with snowfall. In Swansea, in December, during 3.3 snowfall days, 1.42" (36mm) of snow is typically accumulated. Throughout the year, there are 21.2 snowfall days, and 7.17" (182mm) of snow is accumulated.

Daylight

With an average of 9h and 12min of daylight, December has the shortest days of the year.
On the first day of December, sunrise is at 6:53 am and sunset at 4:15 pm. On the last day of the month, sunrise is at 7:11 am and sunset at 4:24 pm EST.

Sunshine

The months with the least sunshine are February and December, with an average of 4.9h of sunshine.

UV index

January through March 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 low health risk from unsafe exposure to UV radiation for ordinary individuals.
Note: A maximum UV index of 2 in December translates into the following recommendations:
Most individuals face no significant issues with extended sun exposure, but it is always essential to protect children, babies, and those with sensitive skin. It's crucial to reduce time in the direct Sun around mid-day due to the intense solar radiation. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation. Remember! The Sun's UV radiation can be magnified almost twofold by the reflection of snow.
Updated: Aug 21, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is it in December?

The high-temperature, in December, in Swansea, is 42.1°F (5.6°C), while the low-temperature averages to 31.8°F (-0.1°C).

What is the average humidity in December?

In December, the average relative humidity is 76%.

How many days does it rain in December in Swansea?

In December, the rain falls for 9.6 days. Throughout December, 1.73" (44mm) of precipitation is accumulated.

How much does it snow in December?

In Swansea, in December, snow falls for 3.3 days, with typically accumulated 1.42" (36mm) of snow.

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.

How many hours of daylight does Swansea have in December?

In December, the average day length is 9h and 13min.

When is the sunrise / sunset in December?

In December, on the first day of the month, sunrise is at 6:53 am and sunset at 4:15 pm. On the last day of the month, sunrise is at 7:11 am and sunset at 4:24 pm EST.

What is the month with the least sunshine?

February and December, with an average of 4.9h of sunshine, are months with the least sunshine.

How many hours of sunshine does Swansea have in December?

The average sunshine duration in December is 4.9h.

When is the lowest UV index?

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

How high is the UV index in December in Swansea?

In December, the average daily maximum UV index in Swansea, Massachusetts, is 2. A UV Index value of 2, and less, symbolizes a low health risk 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
Swansea, MA

Average temperature in December - Swansea, MA
  • Average high temperature in December: 42.1°F

The warmest month (with the highest average high temperature) is July (79.3°F).
The month with the lowest average high temperature is January (36°F).

  • Average low temperature in December: 31.8°F

The month with the highest average low temperature is July (65.5°F).
The coldest month (with the lowest average low temperature) is January (25.2°F).

Average pressure in December
Swansea, MA

Average pressure in December - Swansea, 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
Swansea, MA

Average wind speed in December - Swansea, MA
  • Average wind speed in December: 10.3mph

The windiest months (with the highest average wind speed) are January, February and March (10.9mph).
The calmest month (with the lowest average wind speed) is August (7.3mph).

Average humidity in December
Swansea, MA

Average humidity in December - Swansea, MA
  • Average humidity in December: 76%

The month with the highest relative humidity is June (80%).
The month with the lowest relative humidity is April (73%).

Average rainfall in December
Swansea, MA

Average rainfall in December - Swansea, MA
  • Average rainfall in December: 1.73"

The wettest month (with the highest rainfall) is October (1.97").
The driest month (with the least rainfall) is September (1.06").

Average rainfall days in December
Swansea, MA

Average rainfall days in December - Swansea, MA
  • Average rainfall days in December: 9.6 days

The month with the highest number of rainy days is July (15 days).
The month with the least rainy days is February (6.9 days).

Average snowfall in December
Swansea, MA

Average snowfall in December - Swansea, MA
  • Average snowfall in December: 1.42"

The month with the highest snowfall is March (2.13").
The months with the least snowfall are June, July, August, September and October (0").

Average snowfall days in December
Swansea, MA

Average snowfall days in December - Swansea, MA
  • Average snowfall days in December: 3.3 days

The month with the highest number of snowfall days is January (5.9 days).
The months with the least snowfall days are June, July, August, September and October (0 days).

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

Average daylight in December / Average sunshine in December - Swansea, 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 36min).
The months with the least sunshine are February and December (Average sunshine: 4h and 54min).

Average sunshine days in December
Swansea, MA

Average sunshine days in December - Swansea, MA
  • Average sunshine days in December: 17.6 days

The month with the most sunshine days is November (19.2 days).
The month with the least sunshine days is April (13.6 days).

Average UV index in December
Swansea, MA

Average UV index in December - Swansea, 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 and December (UV index 2).

Average cloud cover in December
Swansea, MA

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

The month with the most cloud cover is March (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 29).

Average visibility in December
Swansea, MA

Average visibility in December - Swansea, 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).

Swansea, Massachusetts, USA

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