December weather forecast
Hartsville, PA

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Weather in December

The first month of the winter, December, is also a frosty month in Hartsville, Pennsylvania, with an average temperature varying between 31.1°F (-0.5°C) and 42.8°F (6°C).

Temperature

December ushers in a slight temperature change, with average high-temperatures reducing from November's fresh 51.8°F (11°C) to a chilly 42.8°F (6°C). Nighttime temperatures in Hartsville hover around an average low of 31.1°F (-0.5°C) in December.

Humidity

The months with the highest humidity are February, October and December, with an average relative humidity of 78%.

Rainfall

The month with the most rainfall is December, when the rain falls for 5.8 days and typically aggregates up to 0.75" (19mm) of precipitation.

Snowfall

Months with snowfall are January through May, November and December. In Hartsville, Pennsylvania, during December, snow falls for 1.7 days and regularly aggregates up to 0.28" (7mm) of snow. In Hartsville, during the entire year, snow falls for 12.6 days and aggregates up to 1.73" (44mm) of snow.

Daylight

With an average of 9h and 24min of daylight, December has the shortest days of the year.
On the first day of the month, sunrise is at 7:04 am and sunset at 4:35 pm. On the last day of December, sunrise is at 7:22 am and sunset at 4:44 pm EST.

Sunshine

In December, the average sunshine is 5h.

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 minimal health hazard from unsafe exposure to UV radiation for ordinary individuals.
Note: A maximum high UV index of 2 in December translates into the following recommendations:
Children must always have sun protection, unlike most people, who can tolerate up to an hour in the sun without any burns. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. For holistic sun protection encompassing the eyes, ears, face, and neck, a wide-brim hat is key. Remember this! The UV radiation of the Sun can be nearly doubled by the reflective properties of snow.
Updated: Jul 28, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

Is it cold during December?

During December, Hartsville experiences an average high-temperature of 42.8°F (6°C) and a low-temperature of 31.1°F (-0.5°C). In August, the average heat index (a.k.a. 'felt air temperature', 'real feel'), which represents the influence of relative humidity on air temperature, is computed to be 89.6°F (32°C).

What are the most humid months?

The months with the highest humidity in Hartsville are February, October and December, with an average relative humidity of 78%.

What is the average humidity in December?

The average relative humidity in December is 78%.

What is the rainiest month?

The month with the most rainfall is December, when the rain falls for 5.8 days and typically aggregates up to 0.75" (19mm) of precipitation.

How many days does it rain in December?

In Hartsville, in December, during 5.8 rainfall days, 0.75" (19mm) of precipitation is typically accumulated.

How many days does it snow in December?

In December, it is snowing for 1.7 days. Throughout December, 0.28" (7mm) of snow is accumulated.

What is the month with the shortest days?

With an average of 9h and 24min of daylight, December has the shortest days of the year.

What is the average length of the day in December in Hartsville?

In December, the average day length is 9h and 22min.

When is the sunrise / sunset in December?

In December, on the first day of the month, sunrise is at 7:04 am and sunset at 4:35 pm. On the last day of the month, sunrise is at 7:22 am and sunset at 4:44 pm EST.

How many hours of sunshine does Hartsville have in December?

In Hartsville, the average sunshine duration in December is 5h.

When is the lowest UV index?

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

What is the UV index reading in December?

In Hartsville, the average daily maximum UV index in December is 2. A UV Index of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's 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
Hartsville, PA

Average temperature in December - Hartsville, PA
  • Average high temperature in December: 42.8°F

The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is January (36.9°F).

  • Average low temperature in December: 31.1°F

The month with the highest average low temperature is July (67.5°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).

Average pressure in December
Hartsville, PA

Average pressure in December - Hartsville, PA
  • Average pressure in December: 30.09"Hg

The month with the highest atmospheric pressure is November (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).

Average wind speed in December
Hartsville, PA

Average wind speed in December - Hartsville, PA
  • Average wind speed in December: 7.5mph

The windiest month (with the highest average wind speed) is March (8.4mph).
The calmest month (with the lowest average wind speed) is August (5.3mph).

Average humidity in December
Hartsville, PA

Average humidity in December - Hartsville, PA
  • Average humidity in December: 78%

The months with the highest relative humidity are February, October and December (78%).
The months with the lowest relative humidity are April, July and August (72%).

Average rainfall in December
Hartsville, PA

Average rainfall in December - Hartsville, PA
  • Average rainfall in December: 0.75"

The wettest month (with the highest rainfall) is December (0.75").
The driest month (with the least rainfall) is September (0.2").

Average rainfall days in December
Hartsville, PA

Average rainfall days in December - Hartsville, PA
  • Average rainfall days in December: 5.8 days

The month with the highest number of rainy days is July (10.3 days).
The month with the least rainy days is January (4.3 days).

Average snowfall in December
Hartsville, PA

Average snowfall in December - Hartsville, PA
  • Average snowfall in December: 0.28"

The month with the highest snowfall is February (0.43").
The months with the least snowfall are June, July, August, September and October (0").

Average snowfall days in December
Hartsville, PA

Average snowfall days in December - Hartsville, PA
  • Average snowfall days in December: 1.7 days

The month with the highest number of snowfall days is February (3.7 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Hartsville, PA

Average daylight in December / Average sunshine in December - Hartsville, PA
  • Average daylight in December: 9h and 2min

The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 24min).

  • Average sunshine in December: 5h and 0min

The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).

Average sunshine days in December
Hartsville, PA

Average sunshine days in December - Hartsville, PA
  • Average sunshine days in December: 23.2 days

The month with the most sunshine days is January (24.3 days).
The month with the least sunshine days is July (17.4 days).

Average UV index in December
Hartsville, PA

Average UV index in December - Hartsville, PA
  • Average UV index in December: 2

The months with the highest UV index are May, 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
Hartsville, PA

Average cloud cover in December - Hartsville, PA
  • Average cloud cover in December: 47

The month with the most cloud cover is February (Cloud cover 48).
The month with the least cloud cover is July (Cloud cover 31).

Average visibility in December
Hartsville, PA

Average visibility in December - Hartsville, PA
  • Average visibility in December: 6mi

The months with the highest visibility are January, February, March, April, June, July, August, October, November and December (6mi).
The months with the lowest visibility are May and September (5mi).

Hartsville, Pennsylvania, USA

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