Will Pipes Freeze in Knox County, MO? 50 nights a Year
Freeze nights in Knox County
In a normal year Knox County, MO gets 50 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 64% of US counties.
Risk level: Severe. The risk season runs November to March, worst in January.
It depends where the pipe is
| Pipe | Freezes near | Nights a year |
|---|---|---|
| Outdoor spigot, open crawlspace | 32°F | 121 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 50 nights |
| Insulated pipe in unheated space | 10°F | 21 nights |
| Inside the heated house | 0°F | 7 nights |
Foam-sleeving a bare pipe in unheated space takes it from 50 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 10/19, last around 04/17. For 20°F: 11/17 to 03/17.
How cold Knox County nights get
Average winter (Dec-Feb) low: 20°F; the coldest month, January, averages 17°F overnight. 7 months normally bring at least one night below 32°F (Jan, Feb, Mar, Apr, 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 7 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 17°F | 20°F | 30°F | 41°F | 52°F | 61°F | 65°F | 63°F | 54°F | 43°F | 31°F | 22°F |
Knox County next to its neighbours
Scotland County, MO, 35 km north, gets 56 nights below 20°F to Knox County's 50 nights. Lewis County, MO, 36 km east, gets 45 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Knox County, MO | - | 121 nights | 50 nights | 17°F |
| Scotland County, MO | 35 km north | 130 nights | 56 nights | 14°F |
| Lewis County, MO | 36 km east | 116 nights | 45 nights | 18°F |
| Shelby County, MO | 38 km south | 124 nights | 49 nights | 17°F |
| Adair County, MO | 39 km west | 126 nights | 55 nights | 15°F |
| Clark County, MO | 46 km northeast | 125 nights | 55 nights | 15°F |
| Schuyler County, MO | 49 km northwest | 128 nights | 57 nights | 15°F |
Knox County within MO
Knox County ranks 27 of 115 MO counties for nights below 20°F. The most is Caldwell County, MO at 65 nights, with a 19°F average winter low. The fewest is Pemiscot County, MO: 14 nights, winter lows near 31°F. At 725 ft, Knox County sits 117 ft below the state's median county elevation of 842 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 Steffenville, MO, 29 km away (fair 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.