Will Pipes Freeze in Slope County, ND? 100 nights a Year
Freeze nights in Slope County
In a normal year Slope County, ND gets 100 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 92% 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 | 182 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 100 nights |
| Insulated pipe in unheated space | 10°F | 56 nights |
| Inside the heated house | 0°F | 28 nights |
Foam-sleeving a bare pipe in unheated space takes it from 100 nights of risk to 56 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 09/29, last around 05/12. For 20°F: 10/25 to 04/12.
How cold Slope County nights get
Average winter (Dec-Feb) low: 10°F; the coldest month, January, averages 7°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, October, November, December: 56 nights a year, and 28 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 7°F | 11°F | 20°F | 30°F | 41°F | 51°F | 57°F | 55°F | 45°F | 32°F | 21°F | 11°F |
Slope County next to its neighbours
Bowman County, ND, 37 km south, gets 106 nights below 20°F to Slope County's 100 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Slope County, ND | - | 182 nights | 100 nights | 7°F |
| Bowman County, ND | 37 km south | 189 nights | 106 nights | 7°F |
| Golden Valley County, ND | 62 km northwest | 185 nights | 102 nights | 6°F |
| Billings County, ND | 63 km north | 183 nights | 103 nights | 6°F |
| Fallon County, MT | 74 km west | 185 nights | 103 nights | 7°F |
| Stark County, ND | 74 km northeast | 192 nights | 112 nights | 5°F |
| Hettinger County, ND | 77 km east | 194 nights | 115 nights | 4°F |
Slope County within ND
Slope County ranks 53 of 53 ND counties for nights below 20°F. The most is Rolette County, ND at 137 nights, with a -3°F average winter low. At 2,783 ft, Slope County sits 1,050 ft above the state's median county elevation of 1,733 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 Amidon, ND, 12 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.