Will Pipes Freeze in Putnam County, IL? 51 nights a Year
Freeze nights in Putnam County
In a normal year Putnam County, IL gets 51 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 65% 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 | 126 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 51 nights |
| Insulated pipe in unheated space | 10°F | 23 nights |
| Inside the heated house | 0°F | 9 nights |
Foam-sleeving a bare pipe in unheated space takes it from 51 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 10/22, last around 04/18. For 20°F: 11/22 to 03/15.
How cold Putnam 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 9 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 16°F | 20°F | 30°F | 40°F | 51°F | 61°F | 64°F | 62°F | 54°F | 43°F | 32°F | 21°F |
Putnam County next to its neighbours
Bureau County, IL, 30 km northwest, gets 55 nights below 20°F to Putnam County's 51 nights. Marshall County, IL, 19 km south, gets 47 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Putnam County, IL | - | 126 nights | 51 nights | 16°F |
| Marshall County, IL | 19 km south | 122 nights | 47 nights | 18°F |
| Bureau County, IL | 30 km northwest | 128 nights | 55 nights | 14°F |
| LaSalle County, IL | 38 km northeast | 130 nights | 55 nights | 15°F |
| Stark County, IL | 43 km west | 141 nights | 64 nights | 14°F |
| Woodford County, IL | 46 km south | 134 nights | 58 nights | 16°F |
| Peoria County, IL | 60 km southwest | 127 nights | 54 nights | 17°F |
Putnam County within IL
Putnam County ranks 39 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 549 ft, Putnam County sits 82 ft below 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 Hennepin, IL, 7 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.