Will Pipes Freeze in Missoula County, MT? 72 nights a Year
Freeze nights in Missoula County
In a normal year Missoula County, MT gets 72 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 78% 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 | 189 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 72 nights |
| Insulated pipe in unheated space | 10°F | 29 nights |
| Inside the heated house | 0°F | 11 nights |
Foam-sleeving a bare pipe in unheated space takes it from 72 nights of risk to 29 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 Missoula County nights get
Average winter (Dec-Feb) low: 16°F; the coldest month, January, averages 16°F overnight. 10 months normally bring at least one night below 32°F (Jan, Feb, Mar, Apr, May, Jun, Sep, Oct, Nov, Dec). Nights below 10°F, cold enough to freeze insulated pipe in an unheated space, come in January, February, March, November, December: 29 nights a year, and 11 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 16°F | 17°F | 24°F | 30°F | 38°F | 44°F | 49°F | 47°F | 41°F | 32°F | 24°F | 16°F |
Missoula County next to its neighbours
Powell County, MT, 76 km east, gets 126 nights below 20°F to Missoula County's 72 nights. Lake County, MT, 70 km north, gets 40 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Missoula County, MT | - | 189 nights | 72 nights | 16°F |
| Lake County, MT | 70 km north | 145 nights | 40 nights | 22°F |
| Powell County, MT | 76 km east | 241 nights | 126 nights | 9°F |
| Granite County, MT | 79 km southeast | 215 nights | 98 nights | 15°F |
| Mineral County, MT | 91 km west | 185 nights | 60 nights | 21°F |
| Ravalli County, MT | 107 km south | 222 nights | 97 nights | 14°F |
| Lewis and Clark County, MT | 115 km east | 189 nights | 80 nights | 15°F |
Missoula County within MT
Missoula County ranks 50 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 6,949 ft, Missoula County sits 3,027 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 Seeley Lake Ranger Station, MT, 35 km away (distant 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.