Will Pipes Freeze in Valley County, MT? 104 nights a Year
Freeze nights in Valley County
In a normal year Valley County, MT gets 104 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 93% 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 | 179 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 104 nights |
| Insulated pipe in unheated space | 10°F | 61 nights |
| Inside the heated house | 0°F | 34 nights |
Foam-sleeving a bare pipe in unheated space takes it from 104 nights of risk to 61 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 09/30, last around 05/06. For 20°F: 10/27 to 04/06.
How cold Valley County nights get
Average winter (Dec-Feb) low: 8°F; the coldest month, January, averages 5°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: 61 nights a year, and 34 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 5°F | 9°F | 21°F | 32°F | 43°F | 52°F | 58°F | 57°F | 46°F | 34°F | 20°F | 9°F |
Valley County next to its neighbours
Daniels County, MT, 97 km northeast, gets 127 nights below 20°F to Valley County's 104 nights. Phillips County, MT, 94 km west, gets 101 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Valley County, MT | - | 179 nights | 104 nights | 5°F |
| Phillips County, MT | 94 km west | 178 nights | 101 nights | 6°F |
| Daniels County, MT | 97 km northeast | 205 nights | 127 nights | 0°F |
| McCone County, MT | 105 km southeast | 183 nights | 99 nights | 7°F |
| Garfield County, MT | 123 km south | 192 nights | 102 nights | 5°F |
| Roosevelt County, MT | 124 km east | 203 nights | 128 nights | 1°F |
| Sheridan County, MT | 162 km east | 203 nights | 129 nights | -2°F |
Valley County within MT
Valley County ranks 15 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 2,387 ft, Valley County sits 1,535 ft below 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 Glasgow International Airport, MT, 16 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.