Will Pipes Freeze in Dane County, WI? 79 nights a Year
Freeze nights in Dane County
In a normal year Dane County, WI gets 79 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 82% 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 | 155 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 79 nights |
| Insulated pipe in unheated space | 10°F | 41 nights |
| Inside the heated house | 0°F | 19 nights |
Foam-sleeving a bare pipe in unheated space takes it from 79 nights of risk to 41 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 10/09, last around 05/01. For 20°F: 11/12 to 04/01.
How cold Dane County nights get
Average winter (Dec-Feb) low: 14°F; the coldest month, January, averages 11°F overnight. 9 months normally bring at least one night below 32°F (Jan, Feb, Mar, Apr, May, Sep, Oct, Nov, Dec). Nights below 10°F, cold enough to freeze insulated pipe in an unheated space, come in January, February, March, November, December: 41 nights a year, and 19 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 11°F | 14°F | 25°F | 36°F | 47°F | 57°F | 62°F | 60°F | 51°F | 39°F | 28°F | 18°F |
Dane County next to its neighbours
Iowa County, WI, 59 km west, gets 83 nights below 20°F to Dane County's 79 nights. Columbia County, WI, 46 km north, gets 79 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Dane County, WI | - | 155 nights | 79 nights | 11°F |
| Columbia County, WI | 46 km north | 154 nights | 79 nights | 9°F |
| Green County, WI | 46 km south | 150 nights | 74 nights | 11°F |
| Rock County, WI | 52 km southeast | 147 nights | 71 nights | 11°F |
| Jefferson County, WI | 53 km east | 144 nights | 73 nights | 11°F |
| Sauk County, WI | 58 km northwest | 149 nights | 75 nights | 10°F |
| Iowa County, WI | 59 km west | 159 nights | 83 nights | 9°F |
Dane County within WI
Dane County ranks 48 of 72 WI counties for nights below 20°F. The most is Vilas County, WI at 116 nights, with a 4°F average winter low. The fewest is Racine County, WI: 55 nights, winter lows near 19°F. At 898 ft, Dane County sits 97 ft below the state's median county elevation of 995 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.
Interior pipes have a threshold too: the four freeze points.
Where this comes from
NOAA 1991-2020 climate normals, blended from 3 nearby stations and adjusted for elevation; closest is Uw Arboretum - Madison, WI, 3 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.