Will Pipes Freeze in Johnston County, NC? 9 nights a Year
Freeze nights in Johnston County
In a normal year Johnston County, NC gets 9 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 25% of US counties.
Risk level: Occasional. The risk season runs December to February, 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 | 9 nights |
| Insulated pipe in unheated space | 10°F | under 1 night |
| Inside the heated house | 0°F | none |
Foam-sleeving a bare pipe in unheated space takes it from 9 nights of risk to under 1 night. 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 11/05, last around 03/29. For 20°F: 12/26 to 02/05.
How cold Johnston County nights get
Average winter (Dec-Feb) low: 33°F; the coldest month, January, averages 31°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: under 1 night a year, and none below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 31°F | 33°F | 39°F | 48°F | 57°F | 66°F | 71°F | 69°F | 63°F | 50°F | 39°F | 34°F |
Johnston County next to its neighbours
Wayne County, NC, 37 km southeast, gets 4 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Johnston County, NC | - | 75 nights | 9 nights | 31°F |
| Wayne County, NC | 37 km southeast | 47 nights | 4 nights | 34°F |
| Wake County, NC | 40 km northwest | 62 nights | 7 nights | 31°F |
| Wilson County, NC | 45 km northeast | 60 nights | 5 nights | 33°F |
| Harnett County, NC | 48 km west | 76 nights | 9 nights | 30°F |
| Sampson County, NC | 58 km south | 59 nights | 6 nights | 32°F |
| Nash County, NC | 61 km northeast | 68 nights | 8 nights | 31°F |
Johnston County within NC
Johnston County ranks 56 of 100 NC counties for nights below 20°F. The most is Swain County, NC at 49 nights, with a 24°F average winter low. The fewest is Carteret County, NC: 3 nights, winter lows near 39°F. At 119 ft, Johnston County sits 354 ft below the state's median county elevation of 473 ft.
What to do here
- Keep a night-of routine: drip, open cabinets, keep the heat at 55F or above.
- Foam-sleeve any pipe in the garage or crawlspace once; it is cheap and lasts years.
Whether foam sleeves are enough here: insulate or heat tape?.
Where this comes from
NOAA 1991-2020 climate normals, blended from 3 nearby stations and adjusted for elevation; closest is Smithfield, NC, 2 km away (close match). A normal year, not tonight's forecast: check the forecast low for the night itself. What a "fair" or "distant" station match means is in the method guide.