Will Pipes Freeze in Gem County, ID? 51 nights a Year
Freeze nights in Gem County
In a normal year Gem County, ID gets 51 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 65% 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 | 157 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 51 nights |
| Insulated pipe in unheated space | 10°F | 15 nights |
| Inside the heated house | 0°F | 4 nights |
Foam-sleeving a bare pipe in unheated space takes it from 51 nights of risk to 15 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 10/12, last around 05/17. For 20°F: 11/18 to 03/04.
How cold Gem County nights get
Average winter (Dec-Feb) low: 21°F; the coldest month, January, averages 20°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, November, December: 15 nights a year, and 4 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 20°F | 23°F | 29°F | 33°F | 40°F | 46°F | 53°F | 52°F | 44°F | 34°F | 26°F | 20°F |
Gem County next to its neighbours
Washington County, ID, 53 km northwest, gets 55 nights below 20°F to Gem County's 51 nights. Payette County, ID, 29 km west, gets 35 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Gem County, ID | - | 157 nights | 51 nights | 20°F |
| Payette County, ID | 29 km west | 138 nights | 35 nights | 23°F |
| Washington County, ID | 53 km northwest | 154 nights | 55 nights | 18°F |
| Canyon County, ID | 54 km southwest | 117 nights | 27 nights | 24°F |
| Boise County, ID | 55 km east | 238 nights | 101 nights | 12°F |
| Ada County, ID | 69 km south | 117 nights | 29 nights | 26°F |
| Adams County, ID | 91 km north | 230 nights | 109 nights | 11°F |
Gem County within ID
Gem County ranks 31 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 4,251 ft, Gem County sits 395 ft below 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.
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 Boise (7 mi N), ID, 39 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.