December weather forecast
Glad Valley, SD

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Weather in December

The first month of the winter, December, is also a subzero cold month in Glad Valley, South Dakota, with an average temperature fluctuating between 16.2°F (-8.8°C) and 28.2°F (-2.1°C).

Temperature

December's arrival signals a significant decrease in average high-temperatures, falling from November's frosty 43.3°F (6.3°C) to a subzero cold 28.2°F (-2.1°C). December sees the temperature falling to a mean low of 16.2°F (-8.8°C).

Humidity

In Glad Valley, the average relative humidity in December is 80%.

Rainfall

In Glad Valley, in December, during 4 rainfall days, 0.83" (21mm) of precipitation is typically accumulated. In Glad Valley, during the entire year, the rain falls for 99.7 days and collects up to 16.06" (408mm) of precipitation.

Snowfall

Months with snowfall are January through May, October through December. In Glad Valley, during December, snow falls for 10.4 days and regularly aggregates up to 3.31" (84mm) of snow. Throughout the year, there are 58.3 snowfall days, and 22.95" (583mm) of snow is accumulated.

Daylight

The month with the shortest days is December, with an average of 8h and 48min of daylight.
On the first day of December, sunrise is at 7:07 am and sunset at 4:05 pm. On the last day of the month, sunrise is at 7:26 am and sunset at 4:14 pm MST.

Sunshine

In December, the average sunshine is 5.1h.

UV index

January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index value of 2, and less, symbolizes a minimal health hazard from exposure to the Sun's UV rays for ordinary individuals.
Note: The UV index of 2 during December translates into the following guidance:
While most people are not greatly affected by extended sun exposure, those with fair skin, babies, and children must always have protection. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. Experience reduced UV exposure by about half when donning a wide-brim hat. Remember to consider! The UV radiation from the Sun can be intensified nearly twice by the reflection of snow.

Frequently asked questions

How cold is December?

The average high-temperature, in December, in Glad Valley, is 28.2°F (-2.1°C), while the average low-temperature is 16.2°F (-8.8°C). The average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which calculates the temperature value influenced by the moisture in the air, in August is estimated at 86°F (30°C).

What is the average humidity in December?

In December, the average relative humidity is 80%.

How much does it rain in December?

In Glad Valley, in December, it is raining for 4 days, with typically 0.83" (21mm) of accumulated precipitation.

How much does it snow in December?

In December, it is snowing for 10.4 days. Throughout December, 3.31" (84mm) of snow is accumulated.

What is the month with the shortest days?

The month with the shortest days is December, with an average of 8h and 48min of daylight.

What is the average length of the day in December?

The average day length in December is 8h and 47min.

When are sunrise and sunset in December?

In December, on the first day of the month, sunrise is at 7:07 am and sunset at 4:05 pm. On the last day of the month, sunrise is at 7:26 am and sunset at 4:14 pm MST.

How many hours of sunshine does Glad Valley have in December?

In Glad Valley, the average sunshine duration in December is 5.1h.

What are the months with the lowest UV index?

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

How high is the UV index in December?

The average daily maximum UV index in December in Glad Valley is 2. A UV Index estimate of 2, and below, represents a low health threat 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
Glad Valley, SD

Average temperature in December - Glad Valley, SD
  • Average high temperature in December: 28.2°F

The warmest month (with the highest average high temperature) is July (87.3°F).
The month with the lowest average high temperature is January (27°F).

  • Average low temperature in December: 16.2°F

The month with the highest average low temperature is July (66°F).
The coldest month (with the lowest average low temperature) is January (13.6°F).

Average pressure in December
Glad Valley, SD

Average pressure in December - Glad Valley, SD
  • Average pressure in December: 30.14"Hg

The months with the highest atmospheric pressure are January and February (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).

Average wind speed in December
Glad Valley, SD

Average wind speed in December - Glad Valley, SD
  • Average wind speed in December: 10.9mph

The windiest month (with the highest average wind speed) is April (12.2mph).
The calmest months (with the lowest average wind speed) are February and August (10.4mph).

Average humidity in December
Glad Valley, SD

Average humidity in December - Glad Valley, SD
  • Average humidity in December: 80%

The month with the highest relative humidity is January (83%).
The months with the lowest relative humidity are August and September (49%).

Average rainfall in December
Glad Valley, SD

Average rainfall in December - Glad Valley, SD
  • Average rainfall in December: 0.83"

The wettest month (with the highest rainfall) is May (2.83").
The driest month (with the least rainfall) is January (0.51").

Average rainfall days in December
Glad Valley, SD

Average rainfall days in December - Glad Valley, SD
  • Average rainfall days in December: 4 days

The month with the highest number of rainy days is May (14.7 days).
The months with the least rainy days are January and February (3.3 days).

Average snowfall in December
Glad Valley, SD

Average snowfall in December - Glad Valley, SD
  • Average snowfall in December: 3.31"

The month with the highest snowfall is February (5.12").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Glad Valley, SD

Average snowfall days in December - Glad Valley, SD
  • Average snowfall days in December: 10.4 days

The month with the highest number of snowfall days is January (12.3 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Glad Valley, SD

Average daylight in December / Average sunshine in December - Glad Valley, SD
  • Average daylight in December: 8h and 5min

The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).

  • Average sunshine in December: 5h and 1min

The month with the most sunshine is July (Average sunshine: 11h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 48min).

Average sunshine days in December
Glad Valley, SD

Average sunshine days in December - Glad Valley, SD
  • Average sunshine days in December: 17.3 days

The month with the most sunshine days is September (20.4 days).
The month with the least sunshine days is April (12.4 days).

Average UV index in December
Glad Valley, SD

Average UV index in December - Glad Valley, SD
  • 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, February, November and December (UV index 2).

Average cloud cover in December
Glad Valley, SD

Average cloud cover in December - Glad Valley, SD
  • Average cloud cover in December: 47

The month with the most cloud cover is January (Cloud cover 50).
The months with the least cloud cover are July and August (Cloud cover 19).

Average visibility in December
Glad Valley, SD

Average visibility in December - Glad Valley, SD
  • 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).

Glad Valley, South Dakota, USA

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