Will Pipes Freeze in Boundary County, ID? 57 nights a Year
Freeze nights in Boundary County
In a normal year Boundary County, ID gets 57 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 70% 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 | 175 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 57 nights |
| Insulated pipe in unheated space | 10°F | 21 nights |
| Inside the heated house | 0°F | 8 nights |
Foam-sleeving a bare pipe in unheated space takes it from 57 nights of risk to 21 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 10/04, last around 04/30. For 20°F: 11/13 to 03/05.
How cold Boundary County nights get
Average winter (Dec-Feb) low: 20°F; the coldest month, January, averages 20°F overnight. 11 months normally bring at least one night below 32°F (Jan, Feb, Mar, Apr, May, Jun, Aug, 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: 21 nights a year, and 8 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 20°F | 21°F | 27°F | 33°F | 40°F | 46°F | 50°F | 48°F | 41°F | 33°F | 27°F | 20°F |
Boundary County next to its neighbours
Lincoln County, MT, 82 km east, gets 61 nights below 20°F to Boundary County's 57 nights. Bonner County, ID, 50 km south, gets 42 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Boundary County, ID | - | 175 nights | 57 nights | 20°F |
| Bonner County, ID | 50 km south | 172 nights | 42 nights | 23°F |
| Pend Oreille County, WA | 58 km southwest | 175 nights | 43 nights | 23°F |
| Lincoln County, MT | 82 km east | 193 nights | 61 nights | 19°F |
| Stevens County, WA | 107 km southwest | 159 nights | 44 nights | 21°F |
| Kootenai County, ID | 123 km south | 139 nights | 29 nights | 25°F |
| Spokane County, WA | 144 km southwest | 135 nights | 31 nights | 25°F |
Boundary County within ID
Boundary County ranks 25 of 44 ID counties for nights below 20°F. The most is Custer County, ID at 145 nights, with a 5°F average winter low. The fewest is Nez Perce County, ID: 20 nights, winter lows near 27°F. At 5,654 ft, Boundary County sits 1,008 ft above the state's median county elevation of 4,646 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 Bonners Ferry, ID, 18 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.