Will Pipes Freeze in Mercer County, IL? 62 nights a Year
Freeze nights in Mercer County
In a normal year Mercer County, IL gets 62 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 73% 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 | 138 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 62 nights |
| Insulated pipe in unheated space | 10°F | 31 nights |
| Inside the heated house | 0°F | 12 nights |
Foam-sleeving a bare pipe in unheated space takes it from 62 nights of risk to 31 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 04/22. For 20°F: 11/16 to 03/21.
How cold Mercer County nights get
Average winter (Dec-Feb) low: 17°F; the coldest month, January, averages 13°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: 31 nights a year, and 12 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 13°F | 17°F | 27°F | 38°F | 50°F | 60°F | 63°F | 62°F | 53°F | 41°F | 30°F | 20°F |
Mercer County next to its neighbours
Rock Island County, IL, 32 km northeast, gets 55 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Mercer County, IL | - | 138 nights | 62 nights | 13°F |
| Rock Island County, IL | 32 km northeast | 126 nights | 55 nights | 14°F |
| Warren County, IL | 41 km south | 132 nights | 57 nights | 14°F |
| Louisa County, IA | 43 km west | 131 nights | 57 nights | 12°F |
| Muscatine County, IA | 44 km northwest | 126 nights | 57 nights | 14°F |
| Henderson County, IL | 47 km south | 121 nights | 52 nights | 16°F |
| Des Moines County, IA | 49 km southwest | 121 nights | 52 nights | 16°F |
Mercer County within IL
Mercer County ranks 11 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 739 ft, Mercer County sits 107 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.
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 Aledo, IL, 1 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.