Will Pipes Freeze in Clark County, SD? 107 nights a Year
Freeze nights in Clark County
In a normal year Clark County, SD gets 107 nights at or below 20°F, the point where bare pipes in a garage, attic or outside wall start to freeze. That is more than 94% of US counties.
Risk level: Severe. The risk season runs October to April, worst in January.
It depends where the pipe is
| Pipe | Freezes near | Nights a year |
|---|---|---|
| Outdoor spigot, open crawlspace | 32°F | 175 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 107 nights |
| Insulated pipe in unheated space | 10°F | 63 nights |
| Inside the heated house | 0°F | 37 nights |
Foam-sleeving a bare pipe in unheated space takes it from 107 nights of risk to 63 nights. A 12 ft heat-tape kit runs $17 to $37; an average burst-pipe repair is about $500.
Month by month
Nights at or below 20°F in a normal year.
First 32°F night is usually around 10/05, last around 05/05. For 20°F: 11/01 to 04/06.
How cold Clark County nights get
Average winter (Dec-Feb) low: 7°F; the coldest month, January, averages 3°F overnight. 9 months normally bring at least one night below 32°F (Jan, Feb, Mar, Apr, May, Sep, Oct, Nov, Dec). Nights below 10°F, cold enough to freeze insulated pipe in an unheated space, come in January, February, March, April, November, December: 63 nights a year, and 37 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 3°F | 7°F | 19°F | 32°F | 45°F | 56°F | 61°F | 58°F | 49°F | 35°F | 21°F | 10°F |
Clark County next to its neighbours
Codington County, SD, 43 km east, gets 113 nights below 20°F to Clark County's 107 nights. Day County, SD, 57 km north, gets 105 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Clark County, SD | - | 175 nights | 107 nights | 3°F |
| Codington County, SD | 43 km east | 181 nights | 113 nights | 2°F |
| Hamlin County, SD | 47 km southeast | 182 nights | 113 nights | 2°F |
| Spink County, SD | 49 km west | 180 nights | 109 nights | 3°F |
| Day County, SD | 57 km north | 167 nights | 105 nights | 3°F |
| Kingsbury County, SD | 58 km south | 165 nights | 97 nights | 5°F |
| Beadle County, SD | 65 km southwest | 167 nights | 96 nights | 6°F |
Clark County within SD
Clark County ranks 10 of 66 SD counties for nights below 20°F. The most is Codington County, SD at 113 nights, with a 6°F average winter low. The fewest is Tripp County, SD: 75 nights, winter lows near 15°F. At 1,787 ft, Clark County sits close to the state's median county elevation of 1,785 ft.
What to do here
- Treat it as a building fix, not a night-of routine: insulate, heat tape, seal crawlspace vents.
- An automatic leak shutoff pays for itself if one burst is avoided.
- Know where the main shutoff is before the first hard freeze.
The dates to be done by: when freeze season starts and ends.
Where this comes from
NOAA 1991-2020 climate normals, blended from 3 nearby stations and adjusted for elevation; closest is Clark, SD, 3 km away (close match). A normal year, not tonight's forecast: check the forecast low for the night itself. What a "fair" or "distant" station match means is in the method guide.