Will Pipes Freeze in McNairy County, TN? 15 nights a Year
Freeze nights in McNairy County
In a normal year McNairy County, TN gets 15 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 32% 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 | 75 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 15 nights |
| Insulated pipe in unheated space | 10°F | 2 nights |
| Inside the heated house | 0°F | under 1 night |
Foam-sleeving a bare pipe in unheated space takes it from 15 nights of risk to 2 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 10/30, last around 04/06. For 20°F: 12/04 to 02/24.
How cold McNairy County nights get
Average winter (Dec-Feb) low: 32°F; the coldest month, January, averages 30°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: 2 nights a year, and under 1 night below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 30°F | 33°F | 40°F | 48°F | 58°F | 66°F | 69°F | 68°F | 61°F | 49°F | 38°F | 33°F |
McNairy County next to its neighbours
Chester County, TN, 28 km north, gets 22 nights below 20°F to McNairy County's 15 nights. Alcorn County, MS, 32 km south, gets 13 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| McNairy County, TN | - | 75 nights | 15 nights | 30°F |
| Chester County, TN | 28 km north | 88 nights | 22 nights | 27°F |
| Alcorn County, MS | 32 km south | 72 nights | 13 nights | 30°F |
| Hardin County, TN | 34 km east | 73 nights | 15 nights | 30°F |
| Hardeman County, TN | 39 km west | 75 nights | 15 nights | 28°F |
| Madison County, TN | 54 km northwest | 72 nights | 15 nights | 28°F |
| Henderson County, TN | 56 km north | 77 nights | 16 nights | 27°F |
McNairy County within TN
McNairy County ranks 78 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 520 ft, McNairy County sits 347 ft below 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.
What insulating actually removes here, and when heat tape is needed: insulate or heat tape?.
Where this comes from
NOAA 1991-2020 climate normals, blended from 3 nearby stations and adjusted for elevation; closest is Selmer, TN, 4 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.