January weather forecast
Custer, SD

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Large, scenic rocks and trees around this tiny Sylvan Lake located in the tranquil Custer State Park in Custer City, South Dakota
Large, scenic rocks and trees around this tiny Sylvan Lake located in the tranquil Custer State Park in Custer City, South Dakota

Weather in January

The New Year begins with fresh snowfall in Custer, South Dakota. Weather conditions in January and February are quite similar, both marked by sub-freezing temperatures and significant snow accumulations. Notably, the lowest temperatures of the year occur in January, with dips down to 17.1°F (-8.3°C) and rarely exceeding 31.1°F (-0.5°C). The city also witnesses its longest snowfall durations this month, blanketing the city in a white hue. A notable degree of cloud cover, amounting to 35%, further accentuates the chilliness of the environment.

Temperature

Custer's January average high-temperature settles at a still subzero cold 31.1°F (-0.5°C), showing a near match with the preceding month. During January, an average low-temperature of 17.1°F (-8.3°C) is observed in Custer.

Humidity

January and February, with an average relative humidity of 77%, are the most humid months in Custer.

Rainfall

January is the month with the least rainfall in Custer. Rain falls for 6.2 days and accumulates 0.47" (12mm) of precipitation.

Snowfall

Months with snowfall in Custer are January through May, September through December. In Custer, in January, during 12.3 snowfall days, 3.54" (90mm) of snow is typically accumulated. Throughout the year, there are 75.1 snowfall days, and 40.24" (1022mm) of snow is accumulated.

Daylight

The average length of the day in January in Custer is 9h and 22min.
On the first day of January in Custer, sunrise is at 7:28 am and sunset at 4:27 pm. On the last day of the month, sunrise is at 7:12 am and sunset at 5:03 pm MST.

Sunshine

In Custer, the average sunshine in January is 6.3h.

UV index

January through March, October through December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index estimate of 2, and below, represents a minimal health hazard from unprotected exposure to Sun's UV rays for average individuals.
Note: The UV index of 2 during January leads to these advisories:
Many can withstand an hour in the sun without burning, yet children must always have protection against sunlight. To avoid the Sun's strongest rays, limit exposure around the mid-day period. Your best bet for sun defense on the face, eyes, and neck is a hat with a wide brim. Bear in mind! The Sun's UV radiation can nearly double in intensity due to the reflective quality of snow.
Updated: Feb 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is it in Custer in January?

In January, the average high-temperature and low-temperature in Custer, South Dakota, are 31.1°F (-0.5°C) and 17.1°F (-8.3°C) respectively.

What are the most humid months in Custer?

January and February, with an average relative humidity of 77%, are most humid months.

What is the average humidity in January in Custer?

The average relative humidity in January in Custer, South Dakota, is 77%.

What is the driest month in Custer?

The month with the least rainfall is January, when the rain falls for 6.2 days and typically collects 0.47" (12mm) of precipitation.

How much does it rain in Custer in January?

In Custer, South Dakota, during January, the rain falls for 6.2 days and regularly aggregates up to 0.47" (12mm) of precipitation.

How many days does it snow in January in Custer?

In Custer, South Dakota, in January, snow falls for 12.3 days, with typically accumulated 3.54" (90mm) of snow.

How many hours of daylight does Custer have in January?

In January, the average day length in Custer is 9h and 22min.

When is the sunrise / sunset in January in Custer?

In January, on the first day of the month, sunrise is at 7:28 am and sunset at 4:27 pm. On the last day of the month, in Custer, sunrise is at 7:12 am and sunset at 5:03 pm MST.

How many hours of sunshine does Custer have in January?

In Custer, South Dakota, the average sunshine duration in January is 6.3h.

What are the months with the lowest UV index in Custer?

January through March, October through December, with an average maximum UV index of 2, are months with the lowest UV index in Custer.

What is the UV index reading in January in Custer?

The average daily maximum UV index in January in Custer, South Dakota, is 2. A UV Index estimate of 2, and below, represents a minimal health vulnerability 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
Custer, SD

Average temperature in January - Custer, SD
  • Average high temperature in January: 31.1°F

The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is December (29.8°F).

  • Average low temperature in January: 17.1°F

The month with the highest average low temperature is July (60.4°F).
The coldest month (with the lowest average low temperature) is February (16.2°F).

Average pressure in January
Custer, SD

Average pressure in January - Custer, SD
  • Average pressure in January: 30.13"Hg

The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).

Average wind speed in January
Custer, SD

Average wind speed in January - Custer, SD
  • Average wind speed in January: 9.2mph

The windiest month (with the highest average wind speed) is April (9.5mph).
The calmest month (with the lowest average wind speed) is August (7mph).

Average humidity in January
Custer, SD

Average humidity in January - Custer, SD
  • Average humidity in January: 77%

The months with the highest relative humidity are January and February (77%).
The months with the lowest relative humidity are August and September (52%).

Average rainfall in January
Custer, SD

Average rainfall in January - Custer, SD
  • Average rainfall in January: 0.47"

The wettest month (with the highest rainfall) is June (3.19").
The driest month (with the least rainfall) is January (0.47").

Average rainfall days in January
Custer, SD

Average rainfall days in January - Custer, SD
  • Average rainfall days in January: 6.2 days

The month with the highest number of rainy days is May (18.6 days).
The month with the least rainy days is November (4.5 days).

Average snowfall in January
Custer, SD

Average snowfall in January - Custer, SD
  • Average snowfall in January: 3.54"

The month with the highest snowfall is April (7.24").
The months with the least snowfall are June, July and August (0").

Average snowfall days in January
Custer, SD

Average snowfall days in January - Custer, SD
  • Average snowfall days in January: 12.3 days

The month with the highest number of snowfall days is February (12.9 days).
The months with the least snowfall days are June, July and August (0 days).

Average daylight in January /
Average sunshine in January
Custer, SD

Average daylight in January / Average sunshine in January - Custer, 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: 9h and 0min).

  • Average sunshine in January: 6h and 2min

The month with the most sunshine is August (Average sunshine: 11h and 42min).
The month with the least sunshine is February (Average sunshine: 6h and 0min).

Average sunshine days in January
Custer, SD

Average sunshine days in January - Custer, SD
  • Average sunshine days in January: 17.4 days

The month with the most sunshine days is November (19.2 days).
The month with the least sunshine days is May (7.8 days).

Average UV index in January
Custer, SD

Average UV index in January - Custer, SD
  • Average UV index in January: 2

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

Average cloud cover in January
Custer, SD

Average cloud cover in January - Custer, SD
  • Average cloud cover in January: 35

The month with the most cloud cover is April (Cloud cover 38).
The month with the least cloud cover is August (Cloud cover 17).

Average visibility in January
Custer, SD

Average visibility in January - Custer, 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).

Custer, South Dakota, USA

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