Will Pipes Freeze in Fallon County, MT? 103 nights a Year
Freeze nights in Fallon County
In a normal year Fallon County, MT gets 103 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 December.
It depends where the pipe is
| Pipe | Freezes near | Nights a year |
|---|---|---|
| Outdoor spigot, open crawlspace | 32°F | 185 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 103 nights |
| Insulated pipe in unheated space | 10°F | 57 nights |
| Inside the heated house | 0°F | 30 nights |
Foam-sleeving a bare pipe in unheated space takes it from 103 nights of risk to 57 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 05/12. For 20°F: 10/23 to 04/13.
How cold Fallon County nights get
Average winter (Dec-Feb) low: 9°F; the coldest month, January, averages 7°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: 57 nights a year, and 30 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 7°F | 10°F | 21°F | 30°F | 41°F | 51°F | 57°F | 54°F | 44°F | 32°F | 20°F | 10°F |
Fallon County next to its neighbours
Bowman County, ND, 73 km east, gets 106 nights below 20°F to Fallon County's 103 nights. Slope County, ND, 74 km east, gets 100 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Fallon County, MT | - | 185 nights | 103 nights | 7°F |
| Wibaux County, MT | 72 km north | 189 nights | 104 nights | 6°F |
| Bowman County, ND | 73 km east | 189 nights | 106 nights | 7°F |
| Slope County, ND | 74 km east | 182 nights | 100 nights | 7°F |
| Golden Valley County, ND | 81 km northeast | 185 nights | 102 nights | 6°F |
| Custer County, MT | 88 km west | 180 nights | 97 nights | 8°F |
| Carter County, MT | 90 km south | 184 nights | 104 nights | 7°F |
Fallon County within MT
Fallon County ranks 18 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 3,030 ft, Fallon County sits 892 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 Baker, MT, 11 km away (close match). A normal year, not tonight's forecast: check the forecast low for the night itself. What a "fair" or "distant" station match means is in the method guide.