Will Pipes Freeze in Teton County, MT? 83 nights a Year
Freeze nights in Teton County
In a normal year Teton County, MT gets 83 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 December.
It depends where the pipe is
| Pipe | Freezes near | Nights a year |
|---|---|---|
| Outdoor spigot, open crawlspace | 32°F | 177 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 83 nights |
| Insulated pipe in unheated space | 10°F | 43 nights |
| Inside the heated house | 0°F | 22 nights |
Foam-sleeving a bare pipe in unheated space takes it from 83 nights of risk to 43 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 09/27, last around 05/16. For 20°F: 10/25 to 04/11.
How cold Teton County nights get
Average winter (Dec-Feb) low: 14°F; the coldest month, January, averages 13°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: 43 nights a year, and 22 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 13°F | 14°F | 20°F | 29°F | 37°F | 45°F | 50°F | 49°F | 41°F | 31°F | 22°F | 15°F |
Teton County next to its neighbours
Toole County, MT, 100 km northeast, gets 109 nights below 20°F to Teton County's 83 nights. Pondera County, MT, 46 km north, gets 82 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Teton County, MT | - | 177 nights | 83 nights | 13°F |
| Pondera County, MT | 46 km north | 173 nights | 82 nights | 13°F |
| Lewis and Clark County, MT | 78 km south | 189 nights | 80 nights | 15°F |
| Cascade County, MT | 89 km southeast | 158 nights | 69 nights | 16°F |
| Toole County, MT | 100 km northeast | 194 nights | 109 nights | 7°F |
| Glacier County, MT | 112 km northwest | 189 nights | 85 nights | 13°F |
| Powell County, MT | 119 km southwest | 241 nights | 126 nights | 9°F |
Teton County within MT
Teton County ranks 43 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 4,103 ft, Teton County sits 181 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 Bynum (4 mi SSE), MT, 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.