Will Pipes Freeze in Stillwater County, MT? 87 nights a Year
Freeze nights in Stillwater County
In a normal year Stillwater County, MT 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 December.
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 | 87 nights |
| Insulated pipe in unheated space | 10°F | 42 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 42 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 09/14, last around 05/27. For 20°F: 10/18 to 04/21.
How cold Stillwater County nights get
Average winter (Dec-Feb) low: 12°F; the coldest month, January, averages 11°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: 42 nights a year, and 19 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 11°F | 13°F | 21°F | 28°F | 37°F | 45°F | 50°F | 48°F | 40°F | 30°F | 19°F | 12°F |
Stillwater County next to its neighbours
Carbon County, MT, 56 km southeast, gets 91 nights below 20°F to Stillwater County's 87 nights. Sweet Grass County, MT, 47 km west, gets 63 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Stillwater County, MT | - | 182 nights | 87 nights | 11°F |
| Sweet Grass County, MT | 47 km west | 153 nights | 63 nights | 20°F |
| Carbon County, MT | 56 km southeast | 183 nights | 91 nights | 11°F |
| Golden Valley County, MT | 82 km north | 181 nights | 87 nights | 14°F |
| Yellowstone County, MT | 91 km east | 181 nights | 89 nights | 12°F |
| Park County, MT | 92 km west | 172 nights | 77 nights | 17°F |
| Wheatland County, MT | 100 km north | 191 nights | 90 nights | 13°F |
Stillwater County within MT
Stillwater County ranks 39 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 3,953 ft, Stillwater County sits close to 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.
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 Columbus, MT, 9 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.