Will Pipes Freeze in Sweet Grass County, MT? 63 nights a Year
Freeze nights in Sweet Grass County
In a normal year Sweet Grass County, MT gets 63 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 73% of US counties.
Risk level: Severe. The risk season runs October to April, worst in December.
It depends where the pipe is
| Pipe | Freezes near | Nights a year |
|---|---|---|
| Outdoor spigot, open crawlspace | 32°F | 153 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 63 nights |
| Insulated pipe in unheated space | 10°F | 30 nights |
| Inside the heated house | 0°F | 14 nights |
Foam-sleeving a bare pipe in unheated space takes it from 63 nights of risk to 30 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 09/26, last around 05/14. For 20°F: 10/26 to 04/06.
How cold Sweet Grass County nights get
Average winter (Dec-Feb) low: 20°F; the coldest month, January, averages 20°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, October, November, December: 30 nights a year, and 14 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 20°F | 20°F | 26°F | 32°F | 40°F | 48°F | 54°F | 51°F | 43°F | 34°F | 26°F | 20°F |
Sweet Grass County next to its neighbours
Stillwater County, MT, 47 km east, gets 87 nights below 20°F to Sweet Grass County's 63 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Sweet Grass County, MT | - | 153 nights | 63 nights | 20°F |
| Stillwater County, MT | 47 km east | 182 nights | 87 nights | 11°F |
| Park County, MT | 60 km southwest | 172 nights | 77 nights | 17°F |
| Wheatland County, MT | 77 km north | 191 nights | 90 nights | 13°F |
| Golden Valley County, MT | 87 km northeast | 181 nights | 87 nights | 14°F |
| Carbon County, MT | 97 km southeast | 183 nights | 91 nights | 11°F |
| Gallatin County, MT | 100 km west | 233 nights | 123 nights | 11°F |
Sweet Grass County within MT
Sweet Grass County ranks 52 of 56 MT counties for nights below 20°F. The most is Sheridan County, MT at 129 nights, with a 2°F average winter low. The fewest is Lake County, MT: 40 nights, winter lows near 22°F. At 4,159 ft, Sweet Grass County sits 237 ft above the state's median county elevation of 3,922 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.
At this many nights, foam alone is not the answer: insulate or heat tape?.
Where this comes from
NOAA 1991-2020 climate normals, blended from 3 nearby stations and adjusted for elevation; closest is Big Timber, MT, 2 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.