Will Pipes Freeze in Walworth County, SD? 105 nights a Year
Freeze nights in Walworth County
In a normal year Walworth County, SD gets 105 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 93% 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 | 178 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 105 nights |
| Insulated pipe in unheated space | 10°F | 59 nights |
| Inside the heated house | 0°F | 33 nights |
Foam-sleeving a bare pipe in unheated space takes it from 105 nights of risk to 59 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 10/01, last around 05/08. For 20°F: 10/27 to 04/12.
How cold Walworth County nights get
Average winter (Dec-Feb) low: 7°F; the coldest month, January, averages 4°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: 59 nights a year, and 33 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 4°F | 8°F | 20°F | 31°F | 44°F | 55°F | 60°F | 58°F | 48°F | 34°F | 21°F | 10°F |
Walworth County next to its neighbours
Campbell County, SD, 40 km north, gets 107 nights below 20°F to Walworth County's 105 nights. Dewey County, SD, 71 km southwest, gets 94 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Walworth County, SD | - | 178 nights | 105 nights | 4°F |
| Campbell County, SD | 40 km north | 178 nights | 107 nights | 3°F |
| Potter County, SD | 42 km south | 176 nights | 105 nights | 5°F |
| Edmunds County, SD | 64 km east | 181 nights | 111 nights | 3°F |
| Dewey County, SD | 71 km southwest | 170 nights | 94 nights | 8°F |
| McPherson County, SD | 75 km northeast | 179 nights | 111 nights | 3°F |
| Sully County, SD | 79 km south | 172 nights | 99 nights | 7°F |
Walworth County within SD
Walworth County ranks 15 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 1,979 ft, Walworth County sits 194 ft above 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 Selby, SD, 9 km away (close match). A normal year, not tonight's forecast: check the forecast low for the night itself. How a county figure is built from stations: how the numbers are made.