Will Pipes Freeze in Granite County, MT? 98 nights a Year
Freeze nights in Granite County
In a normal year Granite County, MT gets 98 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 91% of US counties.
Risk level: Severe. The risk season runs October to May, worst in December.
It depends where the pipe is
| Pipe | Freezes near | Nights a year |
|---|---|---|
| Outdoor spigot, open crawlspace | 32°F | 215 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 98 nights |
| Insulated pipe in unheated space | 10°F | 43 nights |
| Inside the heated house | 0°F | 17 nights |
Foam-sleeving a bare pipe in unheated space takes it from 98 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.
How cold Granite County nights get
Average winter (Dec-Feb) low: 14°F; the coldest month, December, averages 14°F overnight. 12 months normally bring at least one night below 32°F (Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, 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 17 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 15°F | 15°F | 21°F | 27°F | 34°F | 40°F | 45°F | 43°F | 36°F | 28°F | 20°F | 14°F |
Granite County next to its neighbours
Deer Lodge County, MT, 40 km southeast, gets 113 nights below 20°F to Granite County's 98 nights. Ravalli County, MT, 63 km southwest, gets 97 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Granite County, MT | - | 215 nights | 98 nights | 15°F |
| Deer Lodge County, MT | 40 km southeast | 230 nights | 113 nights | 13°F |
| Powell County, MT | 63 km northeast | 241 nights | 126 nights | 9°F |
| Ravalli County, MT | 63 km southwest | 222 nights | 97 nights | 14°F |
| Missoula County, MT | 79 km northwest | 189 nights | 72 nights | 16°F |
| Silver Bow County, MT | 81 km southeast | 235 nights | 127 nights | 9°F |
| Jefferson County, MT | 109 km east | 214 nights | 107 nights | 10°F |
Granite County within MT
Granite County ranks 24 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 6,542 ft, Granite County sits 2,619 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.
The dates to be done by: when freeze season starts and ends.
Where this comes from
NOAA 1991-2020 climate normals, blended from 3 nearby stations and adjusted for elevation; closest is Phillipsburg Ranger Station, MT, 13 km away (fair 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.