Will Pipes Freeze in Johnson County, TN? 41 nights a Year
Freeze nights in Johnson County
In a normal year Johnson County, TN gets 41 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 56% of US counties.
Risk level: Severe. The risk season runs November to April, worst in January.
It depends where the pipe is
| Pipe | Freezes near | Nights a year |
|---|---|---|
| Outdoor spigot, open crawlspace | 32°F | 124 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 41 nights |
| Insulated pipe in unheated space | 10°F | 9 nights |
| Inside the heated house | 0°F | 2 nights |
Foam-sleeving a bare pipe in unheated space takes it from 41 nights of risk to 9 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 10/14, last around 04/27. For 20°F: 11/15 to 03/18.
How cold Johnson County nights get
Average winter (Dec-Feb) low: 25°F; the coldest month, January, averages 23°F overnight. 8 months normally bring at least one night below 32°F (Jan, Feb, Mar, Apr, May, Oct, Nov, Dec). Nights below 10°F, cold enough to freeze insulated pipe in an unheated space, come in January, February, December: 9 nights a year, and 2 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 23°F | 25°F | 31°F | 39°F | 49°F | 56°F | 60°F | 59°F | 53°F | 41°F | 31°F | 26°F |
Johnson County next to its neighbours
Watauga County, NC, 28 km southeast, gets 43 nights below 20°F to Johnson County's 41 nights. Carter County, TN, 30 km southwest, gets 39 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Johnson County, TN | - | 124 nights | 41 nights | 23°F |
| Watauga County, NC | 28 km southeast | 123 nights | 43 nights | 21°F |
| Carter County, TN | 30 km southwest | 118 nights | 39 nights | 23°F |
| Bristol city, VA | 32 km northwest | 108 nights | 30 nights | 24°F |
| Ashe County, NC | 32 km east | 124 nights | 44 nights | 22°F |
| Washington County, VA | 34 km north | 115 nights | 34 nights | 24°F |
| Sullivan County, TN | 40 km west | 93 nights | 22 nights | 26°F |
Johnson County within TN
Johnson County ranks 1 of 95 TN counties for nights below 20°F. The fewest is Hamilton County, TN: 9 nights, winter lows near 34°F. At 2,642 ft, Johnson County sits 1,775 ft above the state's median county elevation of 867 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 Mountain City 2, TN, 6 km away (close 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.