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 18°F (-7.8°C). 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

Stepping into January, Rapid City records an average high-temperature of a still cold 32.7°F (0.4°C), almost consistent with December. During January, Rapid City witnesses a consistent average low-temperature of 18°F (-7.8°C).

Humidity

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

Rainfall

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

Snowfall

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

Daylight

The average length of the day in January is 9h and 20min.
On the first day of January in Rapid City, 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

The average sunshine in January in Rapid City is 6.2h.

UV index

The months with the lowest UV index in Rapid City are January, February, November and December, with an average maximum UV index of 2. A UV Index value of 2, and less, symbolizes a low health risk from unsafe exposure to UV radiation for the average person.
Note: The average daily UV index of 2 in January transforms into the following instructions:
While many people can endure lengthy sun exposure, it remains imperative to safeguard babies, children, and fair-skinned individuals. When the Sun is at its strongest around midday, find shade and limit exposure. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes. Take note! UV radiation from the Sun can double in intensity due to snow reflection.
Updated: Feb 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is January in Rapid City?

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

What is the most humid month in Rapid City?

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

What is the average humidity in January in Rapid City?

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

What is the driest month in Rapid City?

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

How much does it rain in Rapid City in January?

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

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

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

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

The average day length in January in Rapid City is 9h and 20min.

When are sunrise and sunset in January in Rapid City?

On the first day of January, 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 long on average sun shines in January in Rapid City?

The average sunshine duration in January in Rapid City is 6.2h.

When is the lowest UV index in Rapid City?

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

What is the UV index reading in January in Rapid City?

In January, the average daily maximum UV index in Rapid City is 2. A UV Index estimate of 2, and below, represents a low health risk from 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 January
Rapid City, SD

Average temperature in January - Rapid City, SD
  • Average high temperature in January: 32.7°F

The warmest month (with the highest average high temperature) is July (84.7°F).
The month with the lowest average high temperature is December (32.5°F).

  • Average low temperature in January: 18°F

The month with the highest average low temperature is July (63.3°F).
The coldest month (with the lowest average low temperature) is February (17.8°F).

Average pressure in January
Rapid City, SD

Average pressure in January - Rapid City, SD
  • Average pressure in January: 30.14"Hg

The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).

Average wind speed in January
Rapid City, SD

Average wind speed in January - Rapid City, SD
  • Average wind speed in January: 9mph

The windiest month (with the highest average wind speed) is April (10.3mph).
The calmest month (with the lowest average wind speed) is August (8.2mph).

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: 0.43"

The wettest month (with the highest rainfall) is May (2.28").
The driest month (with the least rainfall) is January (0.43").

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: 2.4"

The month with the highest snowfall is April (5.43").
The months with the least snowfall are June, July and August (0").

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: 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).

Rapid City, South Dakota, USA

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