December weather forecast
Plana, SD

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Weather in December

December, the first month of the winter in Plana, is also a subzero cold month, with an average temperature varying between 12.7°F (-10.7°C) and 25°F (-3.9°C).

Temperature

The shift into December is characterized by a noticeable reduction in the average high-temperature, decreasing from November's cold 41.7°F (5.4°C) to a freezing cold 25°F (-3.9°C). December nights cool down to an average low-temperature of 12.7°F (-10.7°C).

Humidity

The average relative humidity in December is 85%.

Rainfall

In December, the rain falls for 3.1 days. Throughout December, 0.87" (22mm) of precipitation is accumulated. In Plana, during the entire year, the rain falls for 97.2 days and collects up to 18.35" (466mm) of precipitation.

Snowfall

Months with snowfall are January through May, October through December. In Plana, in December, snow falls for 11.4 days, with typically accumulated 3.43" (87mm) of snow. In Plana, during the entire year, snow falls for 54.8 days and aggregates up to 19.13" (486mm) of snow.

Daylight

With an average of 8h and 48min of daylight, December has the shortest days of the year.
On the first day of the month, sunrise is at 7:53 am and sunset at 4:51 pm. On the last day of December, sunrise is at 8:13 am and sunset at 4:59 pm CST.

Sunshine

The average sunshine in December is 4.3h.

UV index

In Plana, the average daily maximum UV index in December is 2. A UV Index value of 2, and less, symbolizes a low health risk from exposure to the Sun's UV radiation for the ordinary person.
Note: The UV index of 2 in December translates into these instructions:
Most individuals face no significant issues with extended sun exposure, but it is always essential to protect children, babies, and those with sensitive skin. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. Safeguard your eyes, ears, and face from sun rays with the aid of a wide-brim hat. Foresee this! The reflection from snow can nearly double the intensity of UV radiation from the Sun.
Updated: Aug 31, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is December?

In Plana, in December, the average high-temperature is 25°F (-3.9°C), and the average low-temperature is 12.7°F (-10.7°C). The average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which represents the influence of relative humidity on air temperature, in August is calculated to be 86°F (30°C).

What is the average humidity in December?

The average relative humidity in December in Plana is 85%.

How many days does it rain in December?

In Plana, in December, it is raining for 3.1 days, with typically 0.87" (22mm) of accumulated precipitation.

How many days does it snow in December?

In Plana, during December, snow falls for 11.4 days and regularly aggregates up to 3.43" (87mm) of snow.

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?

In December, the average day length is 8h and 47min.

When are sunrise and sunset in December in Plana?

In December, on the first day of the month, sunrise is at 7:53 am and sunset at 4:51 pm. On the last day of the month, sunrise is at 8:13 am and sunset at 4:59 pm CST.

How long on average sun shines in December?

In Plana, the average sunshine duration in December is 4.3h.

What is the UV index intensity in December?

The average daily maximum UV index in December is 2. A UV Index value of 2, and less, symbolizes a low health threat 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
Plana, SD

Average temperature in December - Plana, SD
  • Average high temperature in December: 25°F

The warmest month (with the highest average high temperature) is July (84.7°F).
The month with the lowest average high temperature is January (20.7°F).

  • Average low temperature in December: 12.7°F

The month with the highest average low temperature is July (63.1°F).
The coldest month (with the lowest average low temperature) is January (6.3°F).

Average pressure in December
Plana, SD

Average pressure in December - Plana, SD
  • Average pressure in December: 30.13"Hg

The month with the highest atmospheric pressure is February (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).

Average wind speed in December
Plana, SD

Average wind speed in December - Plana, SD
  • Average wind speed in December: 9.5mph

The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest month (with the lowest average wind speed) is August (8.3mph).

Average humidity in December
Plana, SD

Average humidity in December - Plana, SD
  • Average humidity in December: 85%

The month with the highest relative humidity is January (88%).
The months with the lowest relative humidity are August and September (60%).

Average rainfall in December
Plana, SD

Average rainfall in December - Plana, SD
  • Average rainfall in December: 0.87"

The wettest month (with the highest rainfall) is June (3.46").
The driest month (with the least rainfall) is January (0.59").

Average rainfall days in December
Plana, SD

Average rainfall days in December - Plana, SD
  • Average rainfall days in December: 3.1 days

The month with the highest number of rainy days is June (15 days).
The month with the least rainy days is February (2 days).

Average snowfall in December
Plana, SD

Average snowfall in December - Plana, SD
  • Average snowfall in December: 3.43"

The month with the highest snowfall is January (3.82").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Plana, SD

Average snowfall days in December - Plana, SD
  • Average snowfall days in December: 11.4 days

The month with the highest number of snowfall days is January (13 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Plana, SD

Average daylight in December / Average sunshine in December - Plana, 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: 4h and 2min

The month with the most sunshine is July (Average sunshine: 11h and 6min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).

Average sunshine days in December
Plana, SD

Average sunshine days in December - Plana, SD
  • Average sunshine days in December: 18.9 days

The month with the most sunshine days is November (20.9 days).
The month with the least sunshine days is June (12.7 days).

Average UV index in December
Plana, SD

Average UV index in December - Plana, SD
  • Average UV index in December: 2

The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February and November (UV index 1).

Average cloud cover in December
Plana, SD

Average cloud cover in December - Plana, SD
  • Average cloud cover in December: 54

The month with the most cloud cover is January (Cloud cover 57).
The months with the least cloud cover are July and August (Cloud cover 23).

Average visibility in December
Plana, SD

Average visibility in December - Plana, SD
  • Average visibility in December: 6mi

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

Plana, South Dakota, USA

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