Will Pipes Freeze in Chester County, PA? 39 nights a Year
Freeze nights in Chester County
In a normal year Chester County, PA gets 39 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 55% 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 | 119 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 39 nights |
| Insulated pipe in unheated space | 10°F | 11 nights |
| Inside the heated house | 0°F | 1 night |
Foam-sleeving a bare pipe in unheated space takes it from 39 nights of risk to 11 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 10/25, last around 04/19. For 20°F: 12/01 to 03/11.
How cold Chester County nights get
Average winter (Dec-Feb) low: 24°F; the coldest month, January, averages 22°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, March, December: 11 nights a year, and 1 night below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 22°F | 23°F | 30°F | 40°F | 50°F | 59°F | 64°F | 62°F | 55°F | 43°F | 34°F | 27°F |
Chester County next to its neighbours
Montgomery County, PA, 42 km northeast, gets 47 nights below 20°F to Chester County's 39 nights. Delaware County, PA, 31 km east, gets 15 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Chester County, PA | - | 119 nights | 39 nights | 22°F |
| Delaware County, PA | 31 km east | 74 nights | 15 nights | 26°F |
| Montgomery County, PA | 42 km northeast | 130 nights | 47 nights | 21°F |
| Lancaster County, PA | 43 km west | 111 nights | 33 nights | 22°F |
| New Castle County, DE | 45 km south | 93 nights | 22 nights | 25°F |
| Cecil County, MD | 49 km south | 95 nights | 24 nights | 25°F |
| Berks County, PA | 51 km north | 107 nights | 33 nights | 23°F |
Chester County within PA
Chester County ranks 56 of 67 PA counties for nights below 20°F. The most is Susquehanna County, PA at 80 nights, with a 15°F average winter low. The fewest is Delaware County, PA: 15 nights, winter lows near 28°F. At 534 ft, Chester County sits 607 ft below the state's median county elevation of 1,141 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 Coatesville (2 mi W), PA, 10 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.