December weather forecast
Fort Mill, SC

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Weather in December

The year in Fort Mill, South Carolina, concludes with December, maintaining a grip on the chill of winter. With average high temperatures dropping down to 53.1°F (11.7°C), it is the coldest month of the year. The advent of winter is marked by the shortest days of the year, with sunlight available for a mere 9.8 hours. Yet, despite the cold, December sparkles with holiday spirit, uplifted by the return of snowfall. Closing the year, it shares its spot with January by featuring the second highest humidity of the year at 75%.

Temperature

December's arrival comes with a mild decrease in the average high-temperature, moving subtly from a refreshing 59.9°F (15.5°C) in November to a fresh 53.1°F (11.7°C). In December, Fort Mill encounters an average low-temperature of 39°F (3.9°C) during the night.

Humidity

With an average relative humidity of 75%, December is the most humid month.

Rainfall

In Fort Mill, in December, it is raining for 10 days, with typically 2.91" (74mm) of accumulated precipitation. In Fort Mill, during the entire year, the rain falls for 146.1 days and collects up to 28.94" (735mm) of precipitation.

Snowfall

January through March and December are months with snowfall. December is the first month it typically snows. Throughout December, in the average 0.5 snowfall days, it receives 0.83" (21mm) of snow. Throughout the year, there are 3.1 snowfall days, and 3.58" (91mm) of snow is accumulated.

Daylight

The month with the shortest days is December, with an average of 9h and 48min of daylight.
On the first day of December, sunrise is at 7:13 am and sunset at 5:12 pm. On the last day of the month, sunrise is at 7:31 am and sunset at 5:22 pm EST.

Sunshine

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

UV index

January and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index of 2, and less, symbolizes a minimal health hazard from exposure to the Sun's UV rays for average individuals.
Note: The UV index of 2 in December translates into these instructions:
While many people can endure lengthy sun exposure, it remains imperative to safeguard babies, children, and fair-skinned individuals. To guard against the harmful effects of the Sun, minimize exposure during midday. Sun-related eye harm can be minimized with proper sunglasses offering UVA and UVB coverage. Be careful! The Sun's UV radiation can nearly be doubled by the reflective quality of snow.
Updated: Aug 22, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are December temperatures?

An average high-temperature, in December, in Fort Mill, is 53.1°F (11.7°C) and the average low-temperature is 39°F (3.9°C). In September, the average heat index (a.k.a. 'apparent temperature', 'feels like'), which combines air temperature and relative humidity, is computed to be 89.6°F (32°C).

What is the most humid month in Fort Mill?

December is the most humid month, with an average relative humidity of 75%.

What is the average humidity in December in Fort Mill?

The average relative humidity in December is 75%.

How much does it rain in December?

In Fort Mill, during December, the rain falls for 10 days and regularly aggregates up to 2.91" (74mm) of precipitation.

When does it start snowing?

December is the first month it typically snows. Throughout December, in the average 0.5 snowfall days, it receives 0.83" (21mm) of snow.

What is the month with the shortest days?

The month with the shortest days is December, with an average of 9h and 48min of daylight.

What is the average length of the day in December?

In December, the average day length in Fort Mill is 9h and 51min.

When is the sunrise / sunset in December?

In December, on the first day of the month, sunrise is at 7:13 am and sunset at 5:12 pm. On the last day of the month, sunrise is at 7:31 am and sunset at 5:22 pm EST.

What is the month with the least sunshine in Fort Mill?

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

How long on average sun shines in December?

In Fort Mill, the average sunshine duration in December is 5.3h.

When is the lowest UV index?

January 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?

The average daily maximum UV index in December is 2. A UV Index estimate of 2, and below, represents a minimal hazard to health from unsafe 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
Fort Mill, SC

Average temperature in December - Fort Mill, SC
  • Average high temperature in December: 53.1°F

The warmest month (with the highest average high temperature) is July (91°F).
The month with the lowest average high temperature is January (49.6°F).

  • Average low temperature in December: 39°F

The month with the highest average low temperature is July (70.7°F).
The coldest month (with the lowest average low temperature) is January (34.3°F).

Average pressure in December
Fort Mill, SC

Average pressure in December - Fort Mill, 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 (29.98"Hg).

Average wind speed in December
Fort Mill, SC

Average wind speed in December - Fort Mill, SC
  • Average wind speed in December: 6.8mph

The windiest months (with the highest average wind speed) are February and April (7.8mph).
The calmest month (with the lowest average wind speed) is August (4.7mph).

Average humidity in December
Fort Mill, SC

Average humidity in December - Fort Mill, SC
  • Average humidity in December: 75%

The month with the highest relative humidity is December (75%).
The month with the lowest relative humidity is July (69%).

Average rainfall in December
Fort Mill, SC

Average rainfall in December - Fort Mill, SC
  • Average rainfall in December: 2.91"

The wettest month (with the highest rainfall) is August (3.23").
The driest months (with the least rainfall) are September and October (1.81").

Average rainfall days in December
Fort Mill, SC

Average rainfall days in December - Fort Mill, SC
  • Average rainfall days in December: 10 days

The month with the highest number of rainy days is July (17.8 days).
The month with the least rainy days is November (8.3 days).

Average snowfall in December
Fort Mill, SC

Average snowfall in December - Fort Mill, SC
  • Average snowfall in December: 0.83"

The month with the highest snowfall is February (1.26").
The months with the least snowfall are April, May, June, July, August, September, October and November (0").

Average snowfall days in December
Fort Mill, SC

Average snowfall days in December - Fort Mill, SC
  • Average snowfall days in December: 0.5 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, October and November (0 days).

Average daylight in December /
Average sunshine in December
Fort Mill, SC

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

The month with the longest days is June (Average daylight: 14h and 30min).
The month with the shortest days is December (Average daylight: 9h and 48min).

  • 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
Fort Mill, SC

Average sunshine days in December - Fort Mill, SC
  • Average sunshine days in December: 19.8 days

The month with the most sunshine days is October (22 days).
The month with the least sunshine days is July (11.8 days).

Average UV index in December
Fort Mill, SC

Average UV index in December - Fort Mill, SC
  • Average UV index in December: 2

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

Average cloud cover in December
Fort Mill, SC

Average cloud cover in December - Fort Mill, SC
  • Average cloud cover in December: 44

The months with the most cloud cover are February and December (Cloud cover 44).
The month with the least cloud cover is June (Cloud cover 30).

Average visibility in December
Fort Mill, SC

Average visibility in December - Fort Mill, 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).

Fort Mill, South Carolina, USA

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