Will Pipes Freeze in New Castle County, DE? 22 nights a Year
Freeze nights in New Castle County
In a normal year New Castle County, DE 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 39% of US counties.
Risk level: Regular. The risk season runs December to March, worst in January.
It depends where the pipe is
| Pipe | Freezes near | Nights a year |
|---|---|---|
| Outdoor spigot, open crawlspace | 32°F | 93 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 22 nights |
| Insulated pipe in unheated space | 10°F | 4 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 4 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 11/01, last around 04/07. For 20°F: 12/13 to 03/04.
How cold New Castle County nights get
Average winter (Dec-Feb) low: 27°F; the coldest month, January, averages 25°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: 4 nights a year, and under 1 night below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 25°F | 26°F | 33°F | 43°F | 53°F | 62°F | 68°F | 66°F | 59°F | 47°F | 37°F | 30°F |
New Castle County next to its neighbours
Cecil County, MD, 26 km west, gets 24 nights below 20°F to New Castle County's 22 nights. Delaware County, PA, 43 km northeast, gets 15 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| New Castle County, DE | - | 93 nights | 22 nights | 25°F |
| Salem County, NJ | 25 km east | 94 nights | 22 nights | 25°F |
| Cecil County, MD | 26 km west | 95 nights | 24 nights | 25°F |
| Delaware County, PA | 43 km northeast | 74 nights | 15 nights | 26°F |
| Chester County, PA | 45 km north | 119 nights | 39 nights | 22°F |
| Gloucester County, NJ | 46 km east | 99 nights | 24 nights | 25°F |
| Cumberland County, NJ | 53 km southeast | 106 nights | 29 nights | 24°F |
New Castle County within DE
New Castle County ranks 1 of 3 DE counties for nights below 20°F. The fewest is Sussex County, DE: 15 nights, winter lows near 30°F. At 42 ft, New Castle County sits close to the state's median county elevation of 42 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 Wilmington New Castle County Airport, DE, 11 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.