Will Pipes Freeze in Williamson County, TN? 22 nights a Year
Freeze nights in Williamson County
In a normal year Williamson County, TN gets 22 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 38% of US counties.
Risk level: Regular. 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 | 86 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 22 nights |
| Insulated pipe in unheated space | 10°F | 3 nights |
| Inside the heated house | 0°F | under 1 night |
Foam-sleeving a bare pipe in unheated space takes it from 22 nights of risk to 3 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 10/31, last around 04/03. For 20°F: 12/08 to 02/24.
How cold Williamson County nights get
Average winter (Dec-Feb) low: 30°F; the coldest month, January, averages 28°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: 3 nights a year, and under 1 night below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 28°F | 31°F | 38°F | 46°F | 55°F | 64°F | 68°F | 67°F | 60°F | 47°F | 37°F | 31°F |
Williamson County next to its neighbours
Maury County, TN, 35 km southwest, gets 23 nights below 20°F to Williamson County's 22 nights. Davidson County, TN, 32 km north, gets 17 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Williamson County, TN | - | 86 nights | 22 nights | 28°F |
| Davidson County, TN | 32 km north | 74 nights | 17 nights | 28°F |
| Maury County, TN | 35 km southwest | 93 nights | 23 nights | 27°F |
| Rutherford County, TN | 44 km east | 93 nights | 24 nights | 27°F |
| Cheatham County, TN | 44 km northwest | 94 nights | 26 nights | 27°F |
| Marshall County, TN | 49 km south | 93 nights | 28 nights | 28°F |
| Dickson County, TN | 50 km northwest | 92 nights | 26 nights | 27°F |
Williamson County within TN
Williamson County ranks 40 of 95 TN counties for nights below 20°F. The most is Johnson County, TN at 41 nights, with a 25°F average winter low. The fewest is Hamilton County, TN: 9 nights, winter lows near 34°F. At 984 ft, Williamson County sits 117 ft above the state's median county elevation of 867 ft.
What to do here
- Insulate every pipe in unheated space before the season starts.
- Heat tape on the runs you cannot insulate well.
- Shut off and drain outdoor spigots for the season.
Why 20°F is the line for a garage pipe: how cold before pipes freeze.
Where this comes from
NOAA 1991-2020 climate normals, blended from 3 nearby stations and adjusted for elevation; closest is Franklin Sewage Plt, TN, 6 km away (close 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.