December weather forecastJefferson, SC

December

Weather in December

December, the first month of the winter in Jefferson, is also a fresh month, with an average temperature fluctuating between 54.3°F (12.4°C) and 40.1°F (4.5°C).

Temperature

December brings a slight decrease in temperature, down from a moderate 60.4°F (15.8°C) in November to a fresh 54.3°F (12.4°C). Jefferson experiences an average low-temperature of 40.1°F (4.5°C) in month of December.

Humidity

The months with the highest humidity in Jefferson are May and December, with an average relative humidity of 75%.

Rainfall

In Jefferson, during December, the rain falls for 11.8 days and regularly aggregates up to 3.43" (87mm) of precipitation. In Jefferson, during the entire year, the rain falls for 166.4 days and collects up to 33.7" (856mm) of precipitation.

Snowfall

Months with snowfall are January through March, November and December. In Jefferson, South Carolina, during December, snow falls for 0.4 days and regularly aggregates up to 0.35" (9mm) of snow. In Jefferson, South Carolina, during the entire year, snow falls for 3.8 days and aggregates up to 2.8" (71mm) of snow.

Daylight

With an average of 9h and 54min of daylight, December has the shortest days of the year in Jefferson.
On the first day of the month, sunrise is at 7:10 am and sunset at 5:10 pm. On the last day of December, in Jefferson, South Carolina, sunrise is at 7:28 am and sunset at 5:21 pm EST.

Sunshine

With an average of 5.5h of sunshine, December has the least sunshine of the year.

UV index

The average daily maximum UV index in December is 3. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for the ordinary person.
Note: The daily high UV index of 3 in December translates into this advice:
Be vigilant - A duty to shield skin and eyes from injury exists. The Sun's UV radiation is especially harmful around midday, so reduce exposure and stay safe. Sunglasses providing both UVA and UVB protection are non-negotiable on sunlit days. Stay alert! Snow's reflective properties can almost double the UV radiation from the Sun.
Updated: Feb 13, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

In December, the average high-temperature and low-temperature are 54.3°F (12.4°C) and 40.1°F (4.5°C) respectively. In September, the average heat index (a.k.a. 'felt air temperature', 'real feel'), which calculates the temperature value influenced by the moisture in the air, is estimated at 87.8°F (31°C).

May and December, with an average relative humidity of 75%, are most humid months in Jefferson.

In December, the average relative humidity in Jefferson is 75%.

In Jefferson, in December, during 11.8 rainfall days, 3.43" (87mm) of precipitation is typically accumulated.

In Jefferson, South Carolina, during December, snow falls for 0.4 days and regularly aggregates up to 0.35" (9mm) of snow.

The month with the shortest days is December, with an average of 9h and 54min of daylight.

The average day length in December in Jefferson is 9h and 53min.

On the first day of December in Jefferson, sunrise is at 7:10 am and sunset at 5:10 pm. On the last day of the month, sunrise is at 7:28 am and sunset at 5:21 pm EST.

The month with the least sunshine in Jefferson, South Carolina, is December, with an average of 5.5h of sunshine.

In December, the average sunshine duration in Jefferson is 5.5h.

The average daily maximum UV index in December is 3. A UV Index of 3 to 5 symbolizes a medium hazard to health from unsafe exposure to Sun's UV rays.
Average high temperature
Average low temperature
Average pressure
Average wind speed
Average max. wind speed
Average wind speed gusts
Average humidity
Average rainfall
Average rainfall days
Average snowfall
Average snowfall days
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Jefferson, SC

  • Average high temperature in December: 54.3°F

The warmest month (with the highest average high temperature) is July (90.1°F).
The month with the lowest average high temperature is January (50.2°F).

  • Average low temperature in December: 40.1°F

The month with the highest average low temperature is July (72°F).
The coldest month (with the lowest average low temperature) is January (35.2°F).

Average pressure in December
Jefferson, SC

  • Average pressure in December: 30.14"Hg

The month with the highest atmospheric pressure is November (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.97"Hg).

Average wind speed in December
Jefferson, SC

  • Average wind speed in December: 6.9mph

The windiest month (with the highest average wind speed) is April (8.3mph).
The calmest month (with the lowest average wind speed) is August (5.1mph).

Average humidity in December
Jefferson, SC

  • Average humidity in December: 75%

The months with the highest relative humidity are May and December (75%).
The months with the lowest relative humidity are January, March, July and November (71%).

Average rainfall in December
Jefferson, SC

  • Average rainfall in December: 3.43"

The wettest month (with the highest rainfall) is August (3.54").
The driest month (with the least rainfall) is October (2.17").

Average rainfall days in December
Jefferson, SC

  • Average rainfall days in December: 11.8 days

The month with the highest number of rainy days is July (19 days).
The month with the least rainy days is October (9.5 days).

Average snowfall in December
Jefferson, SC

  • Average snowfall in December: 0.35"

The month with the highest snowfall is February (1.34").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in December
Jefferson, SC

  • Average snowfall days in December: 0.4 days

The month with the highest number of snowfall days is February (1.4 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
Jefferson, SC

  • Average daylight in December: 9h and 54min

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 30min

The month with the most sunshine is July (Average sunshine: 10h and 54min).
The month with the least sunshine is December (Average sunshine: 5h and 30min).

Average sunshine days in December
Jefferson, SC

  • Average sunshine days in December: 17.4 days

The month with the most sunshine days is October (20.4 days).
The month with the least sunshine days is July (9.7 days).

Average UV index in December
Jefferson, SC

  • Average UV index in December: 3

The months with the highest UV index are June and July (UV index 7).
The month with the lowest UV index is January (UV index 2).

Average cloud cover in December
Jefferson, SC

  • Average cloud cover in December: 41

The months with the most cloud cover are February, March and December (Cloud cover 41).
The month with the least cloud cover is June (Cloud cover 28).

Average visibility in December
Jefferson, 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).