Will Pipes Freeze in Carbon County, MT? 91 nights a Year
Freeze nights in Carbon County
In a normal year Carbon County, MT gets 91 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 88% 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 | 183 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 91 nights |
| Insulated pipe in unheated space | 10°F | 43 nights |
| Inside the heated house | 0°F | 18 nights |
Foam-sleeving a bare pipe in unheated space takes it from 91 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 09/24, last around 05/14. For 20°F: 10/28 to 04/10.
How cold Carbon 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: 43 nights a year, and 18 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 11°F | 13°F | 21°F | 29°F | 39°F | 46°F | 52°F | 50°F | 41°F | 30°F | 20°F | 12°F |
Carbon County next to its neighbours
Park County, WY, 93 km southwest, gets 128 nights below 20°F to Carbon County's 91 nights. Stillwater County, MT, 56 km northwest, gets 87 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Carbon County, MT | - | 183 nights | 91 nights | 11°F |
| Stillwater County, MT | 56 km northwest | 182 nights | 87 nights | 11°F |
| Park County, WY | 93 km southwest | 247 nights | 128 nights | 8°F |
| Sweet Grass County, MT | 97 km northwest | 153 nights | 63 nights | 20°F |
| Yellowstone County, MT | 98 km northeast | 181 nights | 89 nights | 12°F |
| Big Horn County, WY | 113 km southeast | 183 nights | 109 nights | 5°F |
| Big Horn County, MT | 120 km east | 175 nights | 88 nights | 13°F |
Carbon County within MT
Carbon County ranks 31 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 3,907 ft, Carbon 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.
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 Bridger (2 mi N), MT, 15 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.