Will Pipes Freeze in Ontonagon County, MI? 95 nights a Year
Freeze nights in Ontonagon County
In a normal year Ontonagon County, MI gets 95 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 90% 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 | 177 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 95 nights |
| Insulated pipe in unheated space | 10°F | 52 nights |
| Inside the heated house | 0°F | 23 nights |
Foam-sleeving a bare pipe in unheated space takes it from 95 nights of risk to 52 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 10/01, last around 05/27. For 20°F: 11/08 to 04/16.
How cold Ontonagon County nights get
Average winter (Dec-Feb) low: 12°F; the coldest month, February, averages 9°F overnight. 10 months normally bring at least one night below 32°F (Jan, Feb, Mar, Apr, May, Jun, Sep, Oct, Nov, Dec). Nights below 10°F, cold enough to freeze insulated pipe in an unheated space, come in January, February, March, April, November, December: 52 nights a year, and 23 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 9°F | 9°F | 18°F | 30°F | 41°F | 50°F | 55°F | 54°F | 48°F | 37°F | 27°F | 16°F |
Ontonagon County next to its neighbours
Houghton County, MI, 51 km east, gets 96 nights below 20°F to Ontonagon County's 95 nights. Keweenaw County, MI, 92 km northeast, gets 89 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Ontonagon County, MI | - | 177 nights | 95 nights | 9°F |
| Houghton County, MI | 51 km east | 186 nights | 96 nights | 9°F |
| Gogebic County, MI | 55 km southwest | 199 nights | 116 nights | 3°F |
| Baraga County, MI | 71 km east | 195 nights | 115 nights | 6°F |
| Vilas County, WI | 89 km south | 193 nights | 116 nights | 1°F |
| Keweenaw County, MI | 92 km northeast | 169 nights | 89 nights | 11°F |
| Iron County, MI | 93 km southeast | 205 nights | 120 nights | 0°F |
Ontonagon County within MI
Ontonagon County ranks 9 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 783 ft, Ontonagon County sits close to 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.
At this many nights, foam alone is not the answer: insulate or heat tape?.
Where this comes from
NOAA 1991-2020 climate normals, blended from 3 nearby stations and adjusted for elevation; closest is Ontonagon (6 mi SE), MI, 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.