January weather forecastKeystone, SD
January
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 arrival of January is marked by an average high-temperature of a still freezing cold 31.1°F (-0.5°C), bearing a close resemblance to December. An average low-temperature of 17.1°F (-8.3°C) is common during the nights of January.Humidity
January and February, with an average relative humidity of 77%, are the most humid months.Rainfall
The month with the least rainfall is January, when the rain falls for 6.2 days and typically collects 0.47" (12mm) of precipitation.Snowfall
January through May, September through December are months with snowfall in Keystone. In January, it is snowing for 12.3 days. Throughout January, 3.54" (90mm) of snow is accumulated. In Keystone, South Dakota, 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 the month, sunrise is at 7:27 am and sunset at 4:26 pm. On the last day of January, sunrise is at 7:11 am and sunset at 5:02 pm MST.
Sunshine
In January, the average sunshine 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 estimate of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV radiation for the average person.Note: The UV index of 2 during January leads to these advisories:
Sun exposure does not present considerable issues for many, yet infants, fair-skinned people, and children necessitate constant protection. Protect yourself from the midday Sun's peak UV radiation by minimizing exposure. Stay sun-safe with clothing that is both closely woven and worn loosely. Take heed! The reflection of snow can intensify the Sun's UV radiation nearly double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
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).
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).
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).
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%).
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").
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).
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").
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).
Average daylight in January /
Average sunshine in January
Keystone, SD
- Average daylight in January: 9h and 24min
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 18min
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
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).
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).
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).
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).
