Will Pipes Freeze in Portsmouth city, VA? 4 nights a Year
Freeze nights in Portsmouth city
In a normal year Portsmouth city, VA gets 4 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 15% of US counties.
Risk level: Occasional. The risk season runs January to February, worst in January.
It depends where the pipe is
| Pipe | Freezes near | Nights a year |
|---|---|---|
| Outdoor spigot, open crawlspace | 32°F | 42 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 4 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 4 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 11/16, last around 03/23. For 20°F: 01/06 to 02/04.
How cold Portsmouth city nights get
Average winter (Dec-Feb) low: 35°F; the coldest month, January, averages 33°F overnight. 5 months normally bring at least one night below 32°F (Jan, Feb, Mar, Nov, Dec).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 33°F | 35°F | 41°F | 50°F | 59°F | 67°F | 72°F | 71°F | 66°F | 55°F | 44°F | 37°F |
Portsmouth city next to its neighbours
Chesapeake city, VA, 21 km south, gets 16 nights below 20°F to Portsmouth city's 4 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Portsmouth city, VA | - | 42 nights | 4 nights | 33°F |
| Norfolk city, VA | 12 km northeast | 40 nights | 4 nights | 33°F |
| Chesapeake city, VA | 21 km south | 74 nights | 16 nights | 29°F |
| Hampton city, VA | 22 km north | 47 nights | 5 nights | 33°F |
| Newport News city, VA | 28 km northwest | 60 nights | 7 nights | 31°F |
| Poquoson city, VA | 30 km north | 52 nights | 6 nights | 32°F |
| Virginia Beach city, VA | 31 km east | 50 nights | 5 nights | 32°F |
Portsmouth city within VA
Portsmouth city ranks 132 of 133 VA counties for nights below 20°F. The most is Highland County, VA at 62 nights, with a 20°F average winter low. The fewest is Norfolk city, VA: 4 nights, winter lows near 35°F. At 12 ft, Portsmouth city sits 435 ft below the state's median county elevation of 448 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 Norfolk S, VA, 12 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.