Will Pipes Freeze in Henderson County, IL? 52 nights a Year
Freeze nights in Henderson County
In a normal year Henderson County, IL gets 52 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 66% 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 | 121 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 52 nights |
| Insulated pipe in unheated space | 10°F | 23 nights |
| Inside the heated house | 0°F | 8 nights |
Foam-sleeving a bare pipe in unheated space takes it from 52 nights of risk to 23 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 10/29, last around 04/08. For 20°F: 11/26 to 03/12.
How cold Henderson County nights get
Average winter (Dec-Feb) low: 19°F; the coldest month, January, averages 16°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, November, December: 23 nights a year, and 8 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 16°F | 20°F | 30°F | 41°F | 53°F | 63°F | 66°F | 64°F | 56°F | 44°F | 32°F | 22°F |
Henderson County next to its neighbours
Warren County, IL, 27 km east, gets 57 nights below 20°F to Henderson County's 52 nights. Hancock County, IL, 50 km southwest, gets 51 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Henderson County, IL | - | 121 nights | 52 nights | 16°F |
| Des Moines County, IA | 24 km northwest | 121 nights | 52 nights | 16°F |
| Warren County, IL | 27 km east | 132 nights | 57 nights | 14°F |
| McDonough County, IL | 46 km southeast | 134 nights | 58 nights | 15°F |
| Mercer County, IL | 47 km north | 138 nights | 62 nights | 13°F |
| Lee County, IA | 49 km west | 124 nights | 56 nights | 16°F |
| Hancock County, IL | 50 km southwest | 124 nights | 51 nights | 17°F |
Henderson County within IL
Henderson County ranks 34 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 663 ft, Henderson 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.
Interior pipes have a threshold too: the four freeze points.
Where this comes from
NOAA 1991-2020 climate normals, blended from 3 nearby stations and adjusted for elevation; closest is Gladstone Dam 18, IL, 10 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.