Will Pipes Freeze in Winnebago County, IL? 65 nights a Year
Freeze nights in Winnebago County
In a normal year Winnebago County, IL gets 65 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 74% of US counties.
Risk level: Severe. The risk season runs November to April, worst in January.
It depends where the pipe is
| Pipe | Freezes near | Nights a year |
|---|---|---|
| Outdoor spigot, open crawlspace | 32°F | 140 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 65 nights |
| Insulated pipe in unheated space | 10°F | 32 nights |
| Inside the heated house | 0°F | 13 nights |
Foam-sleeving a bare pipe in unheated space takes it from 65 nights of risk to 32 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 10/17, last around 04/24. For 20°F: 11/19 to 03/21.
How cold Winnebago County nights get
Average winter (Dec-Feb) low: 16°F; the coldest month, January, averages 13°F overnight. 8 months normally bring at least one night below 32°F (Jan, Feb, Mar, Apr, May, Oct, Nov, Dec). Nights below 10°F, cold enough to freeze insulated pipe in an unheated space, come in January, February, March, November, December: 32 nights a year, and 13 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 13°F | 16°F | 26°F | 37°F | 48°F | 58°F | 62°F | 60°F | 52°F | 40°F | 29°F | 19°F |
Winnebago County next to its neighbours
Boone County, IL, 28 km east, gets 70 nights below 20°F to Winnebago County's 65 nights. McHenry County, IL, 58 km east, gets 62 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Winnebago County, IL | - | 140 nights | 65 nights | 13°F |
| Boone County, IL | 28 km east | 146 nights | 70 nights | 12°F |
| Ogle County, IL | 35 km south | 140 nights | 65 nights | 13°F |
| Rock County, WI | 38 km north | 147 nights | 71 nights | 11°F |
| Stephenson County, IL | 42 km west | 147 nights | 70 nights | 11°F |
| Green County, WI | 52 km northwest | 150 nights | 74 nights | 11°F |
| McHenry County, IL | 58 km east | 139 nights | 62 nights | 14°F |
Winnebago County within IL
Winnebago County ranks 8 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 822 ft, Winnebago County sits 190 ft above 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.
The dates to be done by: when freeze season starts and ends.
Where this comes from
NOAA 1991-2020 climate normals, blended from 3 nearby stations and adjusted for elevation; closest is Rockford Gtr Rockford Airport, IL, 17 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.