December weather forecast
Irwin, SC

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Weather in December

December, the first month of the winter in Irwin, is still a cool month, with an average temperature fluctuating between 54.1°F (12.3°C) and 39.7°F (4.3°C).

Temperature

December is characterized by a mild reduction in the average high-temperature, from a mild 60.4°F (15.8°C) in November to a cool 54.1°F (12.3°C). Irwin experiences an average nighttime temperature of 39.7°F (4.3°C) in the month of December.

Humidity

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

Rainfall

In Irwin, in December, during 8.5 rainfall days, 1.02" (26mm) of precipitation is typically accumulated. In Irwin, during the entire year, the rain falls for 120.6 days and collects up to 11.97" (304mm) of precipitation.

Snowfall

In Irwin, snow does not fall in March through December.

Daylight

The month with the shortest days is December, with an average of 9h and 54min of daylight.
On the first day of the month, sunrise is at 7:12 am and sunset at 5:12 pm. On the last day of December, sunrise is at 7:30 am and sunset at 5:22 pm EST.

Sunshine

The month with the least sunshine is December, with an average of 5.5h of sunshine.

UV index

The average daily maximum UV index in December is 3. A UV Index value of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV rays for ordinary individuals.
Note: The maximum UV index of 3 during December translates into these guidelines:
Put precautions into practice - Guidance to elude sunburn is provided. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. Be cautious! The UV radiation from the Sun can be magnified almost twofold by snow reflection.
Updated: Jul 18, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are December temperatures?

Irwin in December has an average high-temperature of 54.1°F (12.3°C) and an average low-temperature of 39.7°F (4.3°C). In September, the average heat index (a.k.a. 'real feel', 'apparent temperature'), which calculates the temperature value influenced by the moisture in the air, is calculated to be 89.6°F (32°C).

What is the most humid month?

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

What is the average humidity in December?

The average relative humidity in December is 75%.

How much does it rain in December?

In Irwin, in December, during 8.5 rainfall days, 1.02" (26mm) of precipitation is typically accumulated.

When it does not snow?

March through December are months without snowfall.

Does it snow in December?

In Irwin, in December, it doesn't snow. In January, it regularly snows.

What is the month with the shortest days?

With an average of 9h and 54min of daylight, December has the shortest days of the year in Irwin.

What is the average length of the day in December?

In December, the average day length is 9h and 53min.

When is the sunrise / sunset in December?

On the first day of December, sunrise is at 7:12 am and sunset at 5:12 pm. On the last day of the month, sunrise is at 7:30 am and sunset at 5:22 pm EST.

What is the month with the least sunshine?

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

How long on average sun shines in December?

In December, the average sunshine duration is 5.5h.

What is the UV index reading in December?

The average daily maximum UV index in December is 3. A UV Index estimate of 3 to 5 represents a moderate vulnerability from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Irwin, SC

Average temperature in December - Irwin, SC
  • Average high temperature in December: 54.1°F

The warmest month (with the highest average high temperature) is July (90.3°F).
The month with the lowest average high temperature is January (49.8°F).

  • Average low temperature in December: 39.7°F

The month with the highest average low temperature is July (71.2°F).
The coldest month (with the lowest average low temperature) is January (35.2°F).

Average pressure in December
Irwin, SC

Average pressure in December - Irwin, 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
Irwin, SC

Average wind speed in December - Irwin, SC
  • Average wind speed in December: 6.9mph

The windiest months (with the highest average wind speed) are February and April (8mph).
The calmest month (with the lowest average wind speed) is August (4.8mph).

Average humidity in December
Irwin, SC

Average humidity in December - Irwin, 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 June, July and November (71%).

Average rainfall in December
Irwin, SC

Average rainfall in December - Irwin, SC
  • Average rainfall in December: 1.02"

The wettest month (with the highest rainfall) is August (1.61").
The driest month (with the least rainfall) is September (0.51").

Average rainfall days in December
Irwin, SC

Average rainfall days in December - Irwin, SC
  • Average rainfall days in December: 8.5 days

The month with the highest number of rainy days is July (14.9 days).
The month with the least rainy days is November (5.9 days).

Average snowfall in December
Irwin, SC

Average snowfall in December - Irwin, SC
  • Average snowfall in December: 0"

The month with the highest snowfall is February (0.12").
The months with the least snowfall are March, April, May, June, July, August, September, October, November and December (0").

Average snowfall days in December
Irwin, SC

Average snowfall days in December - Irwin, SC
  • Average snowfall days in December: 0.1 days

The month with the highest number of snowfall days is February (0.5 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
Irwin, SC

Average daylight in December / Average sunshine in December - Irwin, 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 3min

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
Irwin, SC

Average sunshine days in December - Irwin, SC
  • Average sunshine days in December: 20.6 days

The month with the most sunshine days is October (23.5 days).
The month with the least sunshine days is July (12.9 days).

Average UV index in December
Irwin, SC

Average UV index in December - Irwin, 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
Irwin, SC

Average cloud cover in December - Irwin, SC
  • Average cloud cover in December: 41

The month with the most cloud cover is February (Cloud cover 42).
The month with the least cloud cover is June (Cloud cover 28).

Average visibility in December
Irwin, SC

Average visibility in December - Irwin, 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).

Irwin, South Carolina, USA

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