Will Pipes Freeze in St. Clair County, MI? 59 nights a Year
Freeze nights in St. Clair County
In a normal year St. Clair County, MI gets 59 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 71% 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 | 141 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 59 nights |
| Insulated pipe in unheated space | 10°F | 25 nights |
| Inside the heated house | 0°F | 9 nights |
Foam-sleeving a bare pipe in unheated space takes it from 59 nights of risk to 25 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 10/20, last around 05/01. For 20°F: 11/25 to 03/27.
How cold St. Clair County nights get
Average winter (Dec-Feb) low: 19°F; the coldest month, January, averages 17°F overnight. 8 months normally bring at least one night below 32°F (Jan, Feb, Mar, Apr, May, Oct, Nov, Dec). Nights below 10°F, cold enough to freeze insulated pipe in an unheated space, come in January, February, March, December: 25 nights a year, and 9 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 17°F | 17°F | 25°F | 35°F | 47°F | 57°F | 62°F | 60°F | 52°F | 42°F | 32°F | 23°F |
St. Clair County next to its neighbours
Lapeer County, MI, 49 km west, gets 62 nights below 20°F to St. Clair County's 59 nights. Macomb County, MI, 35 km southwest, gets 52 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| St. Clair County, MI | - | 141 nights | 59 nights | 17°F |
| Macomb County, MI | 35 km southwest | 130 nights | 52 nights | 18°F |
| Lapeer County, MI | 49 km west | 145 nights | 62 nights | 15°F |
| Sanilac County, MI | 58 km north | 150 nights | 68 nights | 15°F |
| Oakland County, MI | 66 km southwest | 137 nights | 57 nights | 16°F |
| Genesee County, MI | 85 km west | 147 nights | 62 nights | 16°F |
| Wayne County, MI | 87 km southwest | 131 nights | 51 nights | 18°F |
St. Clair County within MI
St. Clair County ranks 63 of 83 MI counties for nights below 20°F. The most is Iron County, MI at 120 nights, with a 3°F average winter low. The fewest is Allegan County, MI: 38 nights, winter lows near 24°F. At 695 ft, St. Clair County sits 113 ft below the state's median county elevation of 808 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 Richmond (4 mi NNW), MI, 12 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.