Will Pipes Freeze in Cook County, IL? 36 nights a Year
Freeze nights in Cook County
In a normal year Cook County, IL gets 36 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 52% 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 | 98 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 36 nights |
| Insulated pipe in unheated space | 10°F | 14 nights |
| Inside the heated house | 0°F | 3 nights |
Foam-sleeving a bare pipe in unheated space takes it from 36 nights of risk to 14 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 11/05, last around 04/10. For 20°F: 12/01 to 03/10.
How cold Cook County nights get
Average winter (Dec-Feb) low: 23°F; the coldest month, January, averages 20°F overnight. 6 months normally bring at least one night below 32°F (Jan, Feb, Mar, Apr, Nov, Dec). Nights below 10°F, cold enough to freeze insulated pipe in an unheated space, come in January, February, December: 14 nights a year, and 3 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 20°F | 23°F | 31°F | 41°F | 50°F | 60°F | 67°F | 67°F | 60°F | 48°F | 36°F | 25°F |
Cook County next to its neighbours
Lake County, IL, 35 km north, gets 53 nights below 20°F to Cook County's 36 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Cook County, IL | - | 98 nights | 36 nights | 20°F |
| Lake County, IL | 35 km north | 127 nights | 53 nights | 17°F |
| DuPage County, IL | 37 km west | 136 nights | 58 nights | 16°F |
| Lake County, IN | 52 km southeast | 128 nights | 53 nights | 16°F |
| Will County, IL | 57 km southwest | 125 nights | 52 nights | 16°F |
| Porter County, IN | 64 km southeast | 125 nights | 48 nights | 18°F |
| Kane County, IL | 65 km west | 138 nights | 61 nights | 15°F |
Cook County within IL
Cook County ranks 70 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 589 ft, Cook 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.
When to have the house ready: when freeze season starts.
Where this comes from
NOAA 1991-2020 climate normals, blended from 3 nearby stations and adjusted for elevation; closest is Chicago Northerly Island, IL, 5 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.