Will Pipes Freeze in Douglas County, SD? 80 nights a Year
Freeze nights in Douglas County
In a normal year Douglas County, SD gets 80 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 82% 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 | 155 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 80 nights |
| Insulated pipe in unheated space | 10°F | 40 nights |
| Inside the heated house | 0°F | 16 nights |
Foam-sleeving a bare pipe in unheated space takes it from 80 nights of risk to 40 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 10/06, last around 05/03. For 20°F: 11/04 to 04/01.
How cold Douglas County nights get
Average winter (Dec-Feb) low: 13°F; the coldest month, January, averages 10°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, November, December: 40 nights a year, and 16 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 10°F | 14°F | 24°F | 35°F | 47°F | 58°F | 62°F | 60°F | 52°F | 38°F | 25°F | 15°F |
Douglas County next to its neighbours
Davison County, SD, 36 km northeast, gets 87 nights below 20°F to Douglas County's 80 nights. Charles Mix County, SD, 28 km southwest, gets 79 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Douglas County, SD | - | 155 nights | 80 nights | 10°F |
| Charles Mix County, SD | 28 km southwest | 155 nights | 79 nights | 11°F |
| Davison County, SD | 36 km northeast | 158 nights | 87 nights | 9°F |
| Aurora County, SD | 41 km northwest | 162 nights | 90 nights | 8°F |
| Hutchinson County, SD | 50 km east | 157 nights | 85 nights | 9°F |
| Hanson County, SD | 56 km northeast | 159 nights | 87 nights | 6°F |
| Bon Homme County, SD | 59 km southeast | 157 nights | 84 nights | 9°F |
Douglas County within SD
Douglas County ranks 63 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 1,572 ft, Douglas County sits 213 ft below 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.
Interior pipes have a threshold too: the four freeze points.
Where this comes from
NOAA 1991-2020 climate normals, blended from 3 nearby stations and adjusted for elevation; closest is Armour, 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.