December weather forecast
Sumter Junction, SC

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Weather in December

The first month of the winter, December, is still a refreshing month in Sumter Junction, South Carolina, with an average temperature varying between 42.3°F (5.7°C) and 56.3°F (13.5°C).

Temperature

Sumter Junction in December undergoes a slight reduction in the average high-temperature, shifting from November's comfortable 62.4°F (16.9°C) to a moderate 56.3°F (13.5°C). During December, the average low-temperature is recorded at a cold 42.3°F (5.7°C).

Humidity

In December, the average relative humidity is 74%.

Rainfall

The month with the most rainfall is December, when the rain falls for 11 days and typically aggregates up to 3.58" (91mm) of precipitation.

Snowfall

January through March, November and December are months with snowfall. In Sumter Junction, in December, snow falls for 0.1 days, with typically accumulated 0.16" (4mm) of snow. In Sumter Junction, during the entire year, snow falls for 1.3 days and aggregates up to 1.06" (27mm) of snow.

Daylight

With an average of 9h and 54min of daylight, December has the shortest days of the year in Sumter Junction.
On the first day of the month, sunrise is at 7:09 am and sunset at 5:13 pm. On the last day of December, in Sumter Junction, sunrise is at 7:27 am and sunset at 5:24 pm EST.

Sunshine

The month with the least sunshine is December, with an average of 5.3h of sunshine.

UV index

The months with the lowest UV index are January, February and December, with an average maximum UV index of 3. A UV Index estimate of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for average individuals.
Note: The maximum daily UV index, 3 in December, converts into the following recommendations:
Exercise caution. Those with pale skin may experience burns in less than half an hour. Direct exposure to the Sun during its peak hours around mid-day should be minimized for safety. For holistic sun protection encompassing the eyes, ears, face, and neck, a wide-brim hat is key. Take into account! The reflection from snow can nearly double the Sun's UV radiation intensity.
Updated: Jul 11, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the average December temperature?

In December, in Sumter Junction, the average high-temperature is 56.3°F (13.5°C), and the average low-temperature is 42.3°F (5.7°C). The average heat index (a.k.a. 'felt air temperature', 'feels like'), which combines air temperature and relative humidity, in September is estimated at 91.4°F (33°C).

What is the average humidity in December?

In Sumter Junction, the average relative humidity in December is 74%.

What is the rainiest month?

December is the month with the most rainfall. Rain falls for 11 days and accumulates 3.58" (91mm) of precipitation.

How much does it rain in December?

In Sumter Junction, during December, the rain falls for 11 days and regularly aggregates up to 3.58" (91mm) of precipitation.

How many days does it snow in December?

In December, it is snowing for 0.1 days. Throughout December, 0.16" (4mm) of snow is accumulated.

What is the month with the shortest days?

December has the shortest days of the year in Sumter Junction, with an average of 9h and 54min of daylight.

What is the average length of the day in December?

In December, the average day length is 9h and 57min.

When is the sunrise / sunset in December?

In December, on the first day of the month, sunrise is at 7:09 am and sunset at 5:13 pm. On the last day of the month, in Sumter Junction, sunrise is at 7:27 am and sunset at 5:24 pm EST.

What is the month with the least sunshine?

With an average of 5.3h of sunshine, December has the least sunshine of the year.

How many hours of sunshine does Sumter Junction have in December?

In December, the average sunshine duration is 5.3h.

What is the month with the lowest UV index?

January, February and December, with an average maximum UV index of 3, are months with the lowest UV index in Sumter Junction.

How high is the UV index in December?

In December, the average daily maximum UV index is 3. A UV Index estimate of 3 to 5 represents a moderate vulnerability 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
Sumter Junction, SC

Average temperature in December - Sumter Junction, SC
  • Average high temperature in December: 56.3°F

The warmest month (with the highest average high temperature) is July (90.7°F).
The month with the lowest average high temperature is January (52.9°F).

  • Average low temperature in December: 42.3°F

The month with the highest average low temperature is July (72.9°F).
The coldest month (with the lowest average low temperature) is January (38.1°F).

Average pressure in December
Sumter Junction, SC

Average pressure in December - Sumter Junction, SC
  • Average pressure in December: 30.14"Hg

The months with the highest atmospheric pressure are January, November and December (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.97"Hg).

Average wind speed in December
Sumter Junction, SC

Average wind speed in December - Sumter Junction, SC
  • Average wind speed in December: 7.5mph

The windiest months (with the highest average wind speed) are February and April (8.5mph).
The calmest month (with the lowest average wind speed) is August (5.6mph).

Average humidity in December
Sumter Junction, SC

Average humidity in December - Sumter Junction, SC
  • Average humidity in December: 74%

The month with the highest relative humidity is May (76%).
The months with the lowest relative humidity are January and November (70%).

Average rainfall in December
Sumter Junction, SC

Average rainfall in December - Sumter Junction, SC
  • Average rainfall in December: 3.58"

The wettest month (with the highest rainfall) is December (3.58").
The driest month (with the least rainfall) is January (1.89").

Average rainfall days in December
Sumter Junction, SC

Average rainfall days in December - Sumter Junction, SC
  • Average rainfall days in December: 11 days

The month with the highest number of rainy days is July (20.1 days).
The month with the least rainy days is October (8.5 days).

Average snowfall in December
Sumter Junction, SC

Average snowfall in December - Sumter Junction, SC
  • Average snowfall in December: 0.16"

The month with the highest snowfall is February (0.55").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in December
Sumter Junction, SC

Average snowfall days in December - Sumter Junction, SC
  • Average snowfall days in December: 0.1 days

The month with the highest number of snowfall days is February (0.6 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).

Average daylight in December /
Average sunshine in December
Sumter Junction, SC

Average daylight in December / Average sunshine in December - Sumter Junction, SC
  • Average daylight in December: 9h and 5min

The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).

  • Average sunshine in December: 5h and 2min

The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is December (Average sunshine: 5h and 18min).

Average sunshine days in December
Sumter Junction, SC

Average sunshine days in December - Sumter Junction, SC
  • Average sunshine days in December: 18.8 days

The month with the most sunshine days is October (20.8 days).
The month with the least sunshine days is July (8.8 days).

Average UV index in December
Sumter Junction, SC

Average UV index in December - Sumter Junction, SC
  • Average UV index in December: 3

The months with the highest UV index are June and July (UV index 7).
The months with the lowest UV index are January, February and December (UV index 3).

Average cloud cover in December
Sumter Junction, SC

Average cloud cover in December - Sumter Junction, SC
  • Average cloud cover in December: 42

The months with the most cloud cover are February and December (Cloud cover 42).
The month with the least cloud cover is October (Cloud cover 29).

Average visibility in December
Sumter Junction, SC

Average visibility in December - Sumter Junction, SC
  • 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).

Sumter Junction, South Carolina, USA

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