January weather forecast
Keystone, SD

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Weather in January

In Keystone, South Dakota, the year unfolds with chilly weather, making January a cold month compared to subsequent ones. The mercury drops to around 17.1°F (-8.3°C) in the early mornings, marking this as the lowest average temperature of the year. The city faces a period of scant daylight with just over nine hours a day, contributing to the frigid conditions. Snowfall is an important feature of the month, blanketing the region in beautiful white. The next month will bring slight changes to these conditions, though it remains largely consistent with the core winter season.

Temperature

The onset of January in Keystone manifests an average high-temperature of a still freezing cold 31.1°F (-0.5°C), demonstrating a minor variation from the preceding month. During January, Keystone records an average temperature of 17.1°F (-8.3°C) at night.

Humidity

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

Rainfall

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

Snowfall

Months with snowfall in Keystone are January through May, September through December. In Keystone, South Dakota, in January, snow falls for 12.3 days, with typically accumulated 3.54" (90mm) of snow. In Keystone, during the entire year, snow falls for 75.1 days and aggregates up to 40.24" (1022mm) of snow.

Daylight

In Keystone, the average length of the day in January is 9h and 21min.
On the first day of January in Keystone, South Dakota, sunrise is at 7:27 am and sunset at 4:26 pm. On the last day of the month, sunrise is at 7:11 am and sunset at 5:02 pm MST.

Sunshine

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

UV index

The months with the lowest UV index are January through March, October through December, with an average maximum UV index of 2. A UV Index value of 2, and less, symbolizes a minimal health hazard from exposure to the Sun's UV rays for average individuals.
Note: The maximum daily UV index of 2 in January interprets into the following recommendations:
Babies, children, and those with sensitive skin should always avoid extended periods in the sun. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. A wide-brimmed hat provides unparalleled sun protection for sensitive areas like the eyes, ears, and neck. Remember! The Sun's UV radiation can be magnified almost twofold by the reflection of snow.
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Frequently asked questions

How cold is it in Keystone in January?

In Keystone, 31.1°F (-0.5°C) is the average high-temperature and 17.1°F (-8.3°C) is the average low-temperature during January.

What are the most humid months in Keystone?

The months with the highest humidity in Keystone, South Dakota, are January and February, with an average relative humidity of 77%.

What is the average humidity in January in Keystone?

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

What is the driest month in Keystone?

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

How much does it rain in Keystone in January?

In January, in Keystone, the rain falls for 6.2 days. Throughout January, 0.47" (12mm) of precipitation is accumulated.

How many days does it snow in January in Keystone?

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

How many hours of daylight does Keystone have in January?

The average day length in January is 9h and 21min.

When is the sunrise / sunset in January in Keystone?

On the first day of January, sunrise is at 7:27 am and sunset at 4:26 pm. On the last day of the month, sunrise is at 7:11 am and sunset at 5:02 pm MST.

How many hours of sunshine does Keystone have in January?

The average sunshine duration in January is 6.3h.

What is the month with the lowest UV index in Keystone?

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

What is the UV index reading in January in Keystone?

In Keystone, South Dakota, the average daily maximum UV index in January is 2. A UV Index reading of 2, and below, represents a low health threat from unsafe 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
Keystone, SD

Average temperature in January - Keystone, 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).

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Average pressure in January
Keystone, SD

Average pressure in January - Keystone, 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).

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Average wind speed in January
Keystone, SD

Average wind speed in January - Keystone, 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).

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Average humidity in January
Keystone, SD

Average humidity in January - Keystone, 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%).

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Average rainfall in January
Keystone, SD

Average rainfall in January - Keystone, 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").

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Average rainfall days in January
Keystone, SD

Average rainfall days in January - Keystone, 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).

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Average snowfall in January
Keystone, SD

Average snowfall in January - Keystone, 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").

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Average snowfall days in January
Keystone, SD

Average snowfall days in January - Keystone, 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).

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

Average daylight in January / Average sunshine in January - Keystone, 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).

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Average sunshine days in January
Keystone, SD

Average sunshine days in January - Keystone, 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).

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Average UV index in January
Keystone, SD

Average UV index in January - Keystone, 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).

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Average cloud cover in January
Keystone, SD

Average cloud cover in January - Keystone, 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).

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Average visibility in January
Keystone, SD

Average visibility in January - Keystone, 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).

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Keystone, South Dakota, USA

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