Will Pipes Freeze in Gregory County, SD? 87 nights a Year
Freeze nights in Gregory County
In a normal year Gregory County, SD gets 87 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 86% 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 | 164 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 87 nights |
| Insulated pipe in unheated space | 10°F | 44 nights |
| Inside the heated house | 0°F | 19 nights |
Foam-sleeving a bare pipe in unheated space takes it from 87 nights of risk to 44 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 10/03, last around 05/06. For 20°F: 10/31 to 04/07.
How cold Gregory 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: 44 nights a year, and 19 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 10°F | 13°F | 23°F | 34°F | 45°F | 57°F | 62°F | 60°F | 50°F | 37°F | 24°F | 14°F |
Gregory County next to its neighbours
Boyd County, NE, 47 km southeast, gets 83 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Gregory County, SD | - | 164 nights | 87 nights | 10°F |
| Boyd County, NE | 47 km southeast | 161 nights | 83 nights | 11°F |
| Charles Mix County, SD | 50 km east | 155 nights | 79 nights | 11°F |
| Keya Paha County, NE | 53 km southwest | 164 nights | 86 nights | 10°F |
| Tripp County, SD | 58 km west | 148 nights | 75 nights | 13°F |
| Brule County, SD | 62 km north | 163 nights | 88 nights | 10°F |
| Douglas County, SD | 73 km east | 155 nights | 80 nights | 10°F |
Gregory County within SD
Gregory County ranks 53 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 2,084 ft, Gregory County sits 299 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 Gregory, SD, 20 km away (close match). A normal year, not tonight's forecast: check the forecast low for the night itself. Why elevation is part of the blend: how county numbers are made.