January weather forecast
Rapid City, SD

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

Weather in January

Cold weather persists in January, making it integral for residents and tourists in Rapid City, South Dakota to layer up. Some of the coldest temperatures of the year occur during this month with a chilling low at around -7.8°C (18°F). Snowfall adorning the cityscape remains a constant sight, while daylight hours are significantly minimized. East-northeasterly winds lend a sharp edge to the winter chill. This month typically witnesses some of the highest humidity levels of the year.

Temperature

The transition into January in Rapid City marks the average high-temperature at a still icy 0.4°C (32.7°F), differing minimally from December's 0.3°C (32.5°F). In the month of January, Rapid City's average low-temperature falls to a subzero cold -7.8°C (18°F).

Humidity

January is the most humid month, with an average relative humidity of 77%.

Rainfall

The month with the least rainfall is January, when the rain falls for 5.3 days and typically collects 11mm (0.43") of precipitation.

Snowfall

January through May, September through December are months with snowfall. In Rapid City, in January, during 9.4 snowfall days, 61mm (2.4") of snow is typically accumulated. Throughout the year, there are 50.4 snowfall days, and 620mm (24.41") of snow is accumulated.

Daylight

In January, the average length of the day is 9h and 20min.
On the first day of January in Rapid City, South Dakota, sunrise is at 7:27 am and sunset at 4:24 pm. On the last day of the month, sunrise is at 7:11 am and sunset at 5:01 pm MST.

Sunshine

In Rapid City, the average sunshine in January is 6.2h.

UV index

The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2. A UV Index of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV radiation for the average person.
Note: In January, the maximum UV index of 2 transforms into these recommendations:
Despite the majority tolerating prolonged sun exposure, those with sensitive skin, infants, and children demand continual protection. Considering the harmful UV rays from the Sun during midday, it's essential to reduce exposure. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection. Forewarned is forearmed! The Sun's UV radiation can be almost doubled in intensity by snow reflection.
Updated: Aug 19, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is January?

The high-temperature, in January, in Rapid City, records 0.4°C (32.7°F), while the low-temperature is -7.8°C (18°F).

What is the most humid month?

The most humid month in Rapid City is January, with an average relative humidity of 77%.

What is the average humidity in January in Rapid City?

In Rapid City, the average relative humidity in January is 77%.

What is the driest month?

January is the month with the least rainfall. Rain falls for 5.3 days and accumulates 11mm (0.43") of precipitation.

How much does it rain in January?

In January, the rain falls for 5.3 days. Throughout January, 11mm (0.43") of precipitation is accumulated.

How many days does it snow in January?

In Rapid City, during January, snow falls for 9.4 days and regularly aggregates up to 61mm (2.4") of snow.

What is the average length of the day in January?

In January, the average day length is 9h and 20min.

When is the sunrise / sunset in January?

In January, on the first day of the month, sunrise is at 7:27 am and sunset at 4:24 pm. On the last day of the month, sunrise is at 7:11 am and sunset at 5:01 pm MST.

How many hours of sunshine does Rapid City have in January?

In January, the average sunshine duration is 6.2h.

What are the months with the lowest UV index?

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

What is the UV index intensity in January?

The average daily maximum UV index in January is 2. A UV Index value of 2, and less, symbolizes a low health threat from unprotected exposure to 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 January
Rapid City, SD

Average temperature in January - Rapid City, SD
  • Average high temperature in January: 0.4°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 January: -7.8°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).

Average pressure in January
Rapid City, SD

Average pressure in January - Rapid City, SD
  • Average pressure in January: 1020.5mbar

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

Average wind speed in January
Rapid City, SD

Average wind speed in January - Rapid City, SD
  • Average wind speed in January: 14.5km/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).

Average humidity in January
Rapid City, SD

Average humidity in January - Rapid City, SD
  • Average humidity in January: 77%

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

Average rainfall in January
Rapid City, SD

Average rainfall in January - Rapid City, SD
  • Average rainfall in January: 11mm

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

Average rainfall days in January
Rapid City, SD

Average rainfall days in January - Rapid City, SD
  • Average rainfall days in January: 5.3 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).

Average snowfall in January
Rapid City, SD

Average snowfall in January - Rapid City, SD
  • Average snowfall in January: 61mm

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

Average snowfall days in January
Rapid City, SD

Average snowfall days in January - Rapid City, SD
  • Average snowfall days in January: 9.4 days

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

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

Average daylight in January / Average sunshine in January - Rapid City, SD
  • Average daylight in January: 9h and 2min

The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 8h and 54min).

  • Average sunshine in January: 6h and 1min

The month with the most sunshine is August (Average sunshine: 11h and 48min).
The month with the least sunshine is February (Average sunshine: 5h and 54min).

Average sunshine days in January
Rapid City, SD

Average sunshine days in January - Rapid City, SD
  • Average sunshine days in January: 18.3 days

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

Average UV index in January
Rapid City, SD

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

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

Average cloud cover in January
Rapid City, SD

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

The 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).

Average visibility in January
Rapid City, SD

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

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

Rapid City, South Dakota, USA

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