Will Pipes Freeze in Mellette County, SD? 84 nights a Year
Freeze nights in Mellette County
In a normal year Mellette County, SD gets 84 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 84% 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 | 161 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 84 nights |
| Insulated pipe in unheated space | 10°F | 41 nights |
| Inside the heated house | 0°F | 19 nights |
Foam-sleeving a bare pipe in unheated space takes it from 84 nights of risk to 41 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 05/10. For 20°F: 10/29 to 04/12.
How cold Mellette County nights get
Average winter (Dec-Feb) low: 14°F; the coldest month, January, averages 12°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: 41 nights a year, and 19 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 12°F | 14°F | 23°F | 33°F | 45°F | 55°F | 61°F | 59°F | 50°F | 36°F | 24°F | 15°F |
Mellette County next to its neighbours
Todd County, SD, 42 km south, gets 88 nights below 20°F to Mellette County's 84 nights. Jones County, SD, 42 km north, gets 83 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Mellette County, SD | - | 161 nights | 84 nights | 12°F |
| Jones County, SD | 42 km north | 157 nights | 83 nights | 12°F |
| Todd County, SD | 42 km south | 171 nights | 88 nights | 11°F |
| Jackson County, SD | 71 km west | 158 nights | 79 nights | 13°F |
| Tripp County, SD | 75 km east | 148 nights | 75 nights | 13°F |
| Lyman County, SD | 81 km northeast | 166 nights | 90 nights | 9°F |
| Bennett County, SD | 86 km southwest | 174 nights | 88 nights | 12°F |
Mellette County within SD
Mellette County ranks 58 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 2,111 ft, Mellette County sits 325 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 Wood, SD, 24 km away (fair 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.