Will Pipes Freeze in Day County, SD? 105 nights a Year
Freeze nights in Day County
In a normal year Day 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 | 167 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 105 nights |
| Insulated pipe in unheated space | 10°F | 62 nights |
| Inside the heated house | 0°F | 35 nights |
Foam-sleeving a bare pipe in unheated space takes it from 105 nights of risk to 62 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 05/04. For 20°F: 11/01 to 04/06.
How cold Day County nights get
Average winter (Dec-Feb) low: 6°F; the coldest month, January, averages 3°F overnight. 8 months normally bring at least one night below 32°F (Jan, Feb, Mar, Apr, May, 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: 62 nights a year, and 35 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 3°F | 6°F | 19°F | 32°F | 45°F | 56°F | 61°F | 59°F | 50°F | 36°F | 22°F | 9°F |
Day County next to its neighbours
Marshall County, SD, 42 km north, gets 110 nights below 20°F to Day County's 105 nights. Roberts County, SD, 58 km northeast, gets 100 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Day County, SD | - | 167 nights | 105 nights | 3°F |
| Marshall County, SD | 42 km north | 173 nights | 110 nights | 2°F |
| Codington County, SD | 53 km southeast | 181 nights | 113 nights | 2°F |
| Clark County, SD | 57 km south | 175 nights | 107 nights | 3°F |
| Roberts County, SD | 58 km northeast | 169 nights | 100 nights | 4°F |
| Brown County, SD | 65 km northwest | 179 nights | 112 nights | 1°F |
| Grant County, SD | 67 km east | 172 nights | 105 nights | 3°F |
Day County within SD
Day County ranks 14 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 1,835 ft, Day County sits 50 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.
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 Webster, SD, 5 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.