December weather forecast
Rapid City, SD

A scenic panorama of the Rapid City in South Dakota
A scenic panorama of the Rapid City in South Dakota

Weather in December

The first month of the winter, December, is still a cold month in Rapid City, South Dakota, with average temperature varying between 32.5°F (0.3°C) and 18.7°F (-7.4°C).

Temperature

The coldest month is December, with an average high-temperature of 32.5°F (0.3°C) and an average low-temperature of 18.7°F (-7.4°C).

Humidity

In December, the average relative humidity in Rapid City is 74%.

Rainfall

In December, the rain falls for 4.8 days. Throughout December, 0.63" (16mm) of precipitation is accumulated. Throughout the year, in Rapid City, South Dakota, there are 118.8 rainfall days, and 15.39" (391mm) of precipitation is accumulated.

Snowfall

January through May, September through December are months with snowfall. In Rapid City, during December, snow falls for 8.1 days and regularly aggregates up to 2.64" (67mm) of snow. Throughout the year, in Rapid City, there are 50.4 snowfall days, and 24.41" (620mm) of snow is accumulated.

Daylight

The month with the shortest days in Rapid City is December, with an average of 8.9h of daylight.

Sunshine

In December, the average sunshine is 6h.

UV index

Months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2. A UV Index value of 2, and less, symbolizes a minimal health vulnerability from the exposure to the Sun's UV radiation for average individuals.
Note: In December, the average maximum UV index of 2 translate into the following recommendations:
Extended sun exposure is not an issue for the majority. Children, infants, and fair-skinned individuals always need to be protected. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking 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. Beware! The strength of the UV rays is increased nearly double-fold by the reflection of the snow.
[Resources]

FAQ

What is the coldest month in Rapid City?

The coldest month is December, with an average high-temperature of 32.5°F (0.3°C) and an average low-temperature of 18.7°F (-7.4°C).

What is the average humidity in December in Rapid City?

The average relative humidity in December is 74%.

How much does it rain in Rapid City in December?

In Rapid City, South Dakota, in December, it is raining for 4.8 days, with typically 0.63" (16mm) of accumulated precipitation.

How many days does it snow in December in Rapid City?

In Rapid City, during December, snow falls for 8.1 days and regularly aggregates up to 2.64" (67mm) of snow.

What is the month with the shortest days in Rapid City?

The month with the shortest days in Rapid City is December, with an average of 8.9h of daylight.

What is the average length of the day in December in Rapid City?

In Rapid City, South Dakota, the average length of the day in December is 8.9h.

How long on average sun shines in December in Rapid City?

In Rapid City, South Dakota, the average sunshine in December is 6h.

What is the month with the lowest UV index in Rapid City?

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

How high is the UV index in December in Rapid City?

The average daily maximum UV index in December in Rapid City, South Dakota, is 2. A UV Index value of 2, and less, symbolizes a low health risk from the exposure to the Sun's UV rays.

Average temperature in December
Rapid City, SD

Average temperature in December - Rapid City, SD
  • Average high temperature in December: 0.3°C

The warmest month (with the highest average high temperature) is July (29.3°C).
The month with the lowest average high temperature is December (0.3°C).

  • Average low temperature in December: -7.4°C

The month with the highest average low temperature is July (17.4°C).
The coldest month (with the lowest average low temperature) is February (-7.9°C).

[Resources]

Average pressure in December
Rapid City, SD

Average pressure in December - Rapid City, SD
  • Average pressure in December: 1020.2mbar

The month with the highest atmospheric pressure is January (1020.5mbar).
The month with the lowest atmospheric pressure is June (1010.6mbar).

[Resources]

Average wind speed in December
Rapid City, SD

Average wind speed in December - Rapid City, SD
  • Average wind speed in December: 14.4km/h

The windiest month (with the highest average wind speed) is April (16.5km/h).
The calmest month (with the lowest average wind speed) is August (13.2km/h).

[Resources]

Average humidity in December
Rapid City, SD

Average humidity in December - Rapid City, SD
  • Average humidity in December: 74%

The month with the highest relative humidity is January (77%).
Months with the lowest relative humidity are August and September (50%).

[Resources]

Average rainfall in December
Rapid City, SD

Average rainfall in December - Rapid City, SD
  • Average rainfall in December: 16mm

The wettest month (with the highest rainfall) is May (58mm).
The driest month (with the least rainfall) is January (11mm).

[Resources]

Average rainfall days in December
Rapid City, SD

Average rainfall days in December - Rapid City, SD
  • Average rainfall days in December: 4.8 days

The month with the highest number of rainy days is May (17.1 days).
The month with the least rainy days is December (4.8 days).

[Resources]

Average snowfall in December
Rapid City, SD

Average snowfall in December - Rapid City, SD
  • Average snowfall in December: 67mm

The month with the highest snowfall is April (138mm).
Months with the least snowfall are June, July and August (0mm).

[Resources]

Average snowfall days in December
Rapid City, SD

Average snowfall days in December - Rapid City, SD
  • Average snowfall days in December: 8.1 days

The month with the highest number of snowfall days is February (10.5 days).
Months with the least snowfall days are June, July and August (0 days).

[Resources]

Average daylight in December /
Average sunshine in December
Rapid City, SD

Average daylight in December / Average sunshine in December - Rapid City, SD
  • Average daylight in December: 8.9h

The month with the longest days is June (Average daylight: 15.4h).
The month with the shortest days is December (Average daylight: 8.9h).

  • Average sunshine in December: 6h

The month with the most sunshine is August (Average sunshine: 11.8h).
The month with the least sunshine is February (Average sunshine: 5.9h).

[Resources]

Average sunshine days in December
Rapid City, SD

Average sunshine days in December - Rapid City, SD
  • Average sunshine days in December: 19.6 days

The month with the most sunshine days is November (20.2 days).
The month with the least sunshine days is May (11 days).

[Resources]

Average UV index in December
Rapid City, SD

Average UV index in December - Rapid City, SD
  • Average UV index in December: 2

Months with the highest UV index are June and July (UV index 6).
Months with the lowest UV index are January, February, November and December (UV index 2).

[Resources]

Average cloud cover in December
Rapid City, SD

Average cloud cover in December - Rapid City, SD
  • Average cloud cover in December: 36

Months with the most cloud cover are February and April (Cloud cover 38).
The month with the least cloud cover is August (Cloud cover 16).

[Resources]

Average visibility in December
Rapid City, SD

Average visibility in December - Rapid City, SD
  • Average visibility in December: 9km

Months with the highest visibility are June, July, August, September and October (10km).
Months with the lowest visibility are January, February, March, April, May, November and December (9km).

[Resources]

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location
* you will be automatically redirected to the weather forecast for your location