Will Pipes Freeze in Monroe County, IL? 33 nights a Year
Freeze nights in Monroe County
In a normal year Monroe County, IL gets 33 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 48% 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 | 102 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 33 nights |
| Insulated pipe in unheated space | 10°F | 10 nights |
| Inside the heated house | 0°F | 2 nights |
Foam-sleeving a bare pipe in unheated space takes it from 33 nights of risk to 10 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 10/26, last around 04/09. For 20°F: 11/29 to 03/08.
How cold Monroe County nights get
Average winter (Dec-Feb) low: 25°F; the coldest month, January, averages 23°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, December: 10 nights a year, and 2 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 23°F | 26°F | 34°F | 44°F | 55°F | 63°F | 68°F | 66°F | 57°F | 46°F | 35°F | 27°F |
Monroe County next to its neighbours
Jefferson County, MO, 32 km west, gets 34 nights below 20°F to Monroe County's 33 nights. St. Clair County, IL, 31 km northeast, gets 28 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Monroe County, IL | - | 102 nights | 33 nights | 23°F |
| St. Clair County, IL | 31 km northeast | 94 nights | 28 nights | 24°F |
| Jefferson County, MO | 32 km west | 104 nights | 34 nights | 22°F |
| Randolph County, IL | 40 km southeast | 106 nights | 33 nights | 22°F |
| St. Louis city, MO | 40 km north | 83 nights | 26 nights | 24°F |
| Ste. Genevieve County, MO | 44 km south | 105 nights | 34 nights | 23°F |
| St. Louis County, MO | 47 km northwest | 93 nights | 31 nights | 23°F |
Monroe County within IL
Monroe County ranks 82 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 647 ft, Monroe County sits close to the state's median county elevation of 632 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.
What insulating actually removes here, and when heat tape is needed: insulate or heat tape?.
Where this comes from
NOAA 1991-2020 climate normals, blended from 3 nearby stations and adjusted for elevation; closest is Festus, MO, 20 km away (close match). A normal year, not tonight's forecast: check the forecast low for the night itself. Why elevation is part of the blend: how county numbers are made.