Keystone, SD weather in January
In January, Keystone sees highs around 36°F and lows around 11°F: cold and mostly dry, with some snow. Rain or snow falls on about 6 days. Snowfall averages about 5.7 in. It is one of the coldest months in Keystone.
- Normal high
- 36°F
- Normal low
- 11°F
- Wet days
- 6
- 0.3 in total
- Snowfall
- 5.7 in
- snow on the ground 18 days
How January changes from start to finish
| January 1 | January 31 | |
|---|---|---|
| Normal high | 36°F | 35°F |
| Normal low | 12°F | 11°F |
| Chance of a wet day | 18% | 21% |
| Sunrise / sunset | 7:28 am / 4:26 pm | 7:11 am / 5:02 pm |
| Daylight | 9.0 h | 9.8 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Mountain Time).
A typical January day
- 6 am22°Fdew point 10°F
- 9 am25°Fdew point 12°F
- Noon32°Fdew point 13°F
- 3 pm32°Fdew point 13°F
- 6 pm25°Fdew point 12°F
- 9 pm23°Fdew point 11°F
NOAA hourly normals (local standard time) from Custer Co Airport (15 mi away); average wind 7 mph; clear or few clouds in 46% of daytime hours, mostly cloudy or overcast in 44%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F0 of 31
- Hot dayshigh 90°F or more0 of 31
- Muggy daysdaily mean dew point 65°F or more0 of 31
- Wet daysat least 0.01 in of rain or melted snow6 of 31
- Notable rainat least 0.10 in1 of 31
- Freezing nightslow 32°F or below31 of 31
- Snow on the groundsnow depth 1 in or more18 of 31
Average days per January, counted from daily records for each year 1991-2020.
Rain and snow in January
Normal precipitation is 0.3 in; a dry January brings about 0.2 in and a wet one about 0.5 in (25th and 75th percentiles). Days with half an inch or more are rare. Normal snowfall is 5.7 in, with about 2 days of an inch or more.
How January varies from year to year
- Warmest January, 1991-20202006: average high 45°F
- Coolest January1996: average high 27°F
- Wettest January2003: 0.7 in
- Driest January1995: 0.02 in
- Highest reading69°F (January 28, 2015)
- Lowest reading-23°F (January 31, 1996)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
January compared with December and February
| December | January | February | |
|---|---|---|---|
| Normal high | 37°F | 36°F | 36°F |
| Normal low | 13°F | 11°F | 11°F |
| Wet days | 5 | 6 | 7 |
| Comfortable days | 0 | 0 | 0 |
| Daylight | 9.0 h | 9.3 h | 10.5 h |
Highs change by -1°F from December and 0°F into February.
Nearby alternatives in January
- Warmer: Fort Collins, CO244 mi · high 45°F · 4 wet days
- Cooler: Medora, ND209 mi · high 28°F · 6 wet days
How Keystone ranks in January
- Normal high295th warmest of 378 cities; 2nd of 4 in South Dakota
- Wet days58th driest of 378
- Comfortable days247th most of 339
What to pack for Keystone in January
- A warm jacket – lows near 11°F, highs near 36°F
- Layers – afternoons near 36°F but nights near 11°F
- Waterproof boots – snow on the ground on about 18 days
- A hat and gloves – about 31 freezing nights
Heating and cooling
January has 1283 heating degree days and 0 cooling degree days (base 65°F), 15% of the year's total heating and cooling demand.
Questions
How cold is Keystone in January?
The normal high is 36°F and the normal low is 11°F. From 1991 to 2020 the coldest January reading was -23°F (January 31, 1996).
Does it rain a lot in Keystone in January?
About 6 days in January have at least 0.01 in of precipitation, and the normal total is 0.3 in. The wettest January in 1991-2020 was in 2003 (0.7 in); the driest was in 1995 (0.02 in).
Does it snow in Keystone in January?
Yes. Normal snowfall in January is 5.7 in, and snow covers the ground on about 18 days.
Is January a good time to visit Keystone?
January ranks 11th of 12 months on our comfort score for Keystone (33 out of 100). It has almost no comfortable days. The best month is June.
Where the numbers come from
- Temperature, rain, snowfall, snow depth and frost dates: Pactola Dam (USC00396427), 12 mi NNW of the city center, 4,720 ft (385 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Humidity and wind by hour: Custer Co Airport (USW00094032), 15 mi SW of the city center, 5,545 ft (1,210 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Cloud cover: Ellsworth AFB (USW00024006), 24 mi NE of the city center, 3,215 ft (1,120 ft lower than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Rapid City Regional Airport (726620-24090), 21 mi ENE of the city center, 3,162 ft (1,173 ft lower than the city). Hourly observations, 1991-2020.