Will Pipes Freeze in Jersey County, IL? 42 nights a Year
Freeze nights in Jersey County
In a normal year Jersey County, IL gets 42 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 58% of US counties.
Risk level: Severe. 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 | 117 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 42 nights |
| Insulated pipe in unheated space | 10°F | 15 nights |
| Inside the heated house | 0°F | 4 nights |
Foam-sleeving a bare pipe in unheated space takes it from 42 nights of risk to 15 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 10/19, last around 04/14. For 20°F: 11/22 to 03/14.
How cold Jersey County nights get
Average winter (Dec-Feb) low: 22°F; the coldest month, January, averages 19°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: 15 nights a year, and 4 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 19°F | 23°F | 32°F | 42°F | 54°F | 63°F | 66°F | 63°F | 55°F | 43°F | 33°F | 24°F |
Jersey County next to its neighbours
Greene County, IL, 31 km north, gets 45 nights below 20°F to Jersey County's 42 nights. Calhoun County, IL, 28 km west, gets 39 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Jersey County, IL | - | 117 nights | 42 nights | 19°F |
| Calhoun County, IL | 28 km west | 109 nights | 39 nights | 20°F |
| Greene County, IL | 31 km north | 120 nights | 45 nights | 18°F |
| Macoupin County, IL | 43 km northeast | 109 nights | 39 nights | 19°F |
| St. Charles County, MO | 43 km southwest | 104 nights | 37 nights | 21°F |
| Madison County, IL | 49 km southeast | 86 nights | 28 nights | 23°F |
| St. Louis County, MO | 49 km south | 93 nights | 31 nights | 23°F |
Jersey County within IL
Jersey County ranks 59 of 102 IL counties for nights below 20°F. The most is Jo Daviess County, IL at 76 nights, with a 14°F average winter low. The fewest is Alexander County, IL: 21 nights, winter lows near 29°F. At 597 ft, Jersey County sits close to the state's median county elevation of 632 ft.
What to do here
- Treat it as a building fix, not a night-of routine: insulate, heat tape, seal crawlspace vents.
- An automatic leak shutoff pays for itself if one burst is avoided.
- Know where the main shutoff is before the first hard freeze.
At this many nights, foam alone is not the answer: insulate or heat tape?.
Where this comes from
NOAA 1991-2020 climate normals, blended from 3 nearby stations and adjusted for elevation; closest is Jerseyville (2 mi SW), IL, 3 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.