Will Pipes Freeze in Lyon County, IA? 96 nights a Year
Freeze nights in Lyon County
In a normal year Lyon County, IA gets 96 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 October to April, worst in January.
It depends where the pipe is
| Pipe | Freezes near | Nights a year |
|---|---|---|
| Outdoor spigot, open crawlspace | 32°F | 168 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 96 nights |
| Insulated pipe in unheated space | 10°F | 54 nights |
| Inside the heated house | 0°F | 28 nights |
Foam-sleeving a bare pipe in unheated space takes it from 96 nights of risk to 54 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 10/04, last around 05/01. For 20°F: 11/03 to 04/03.
How cold Lyon County nights get
Average winter (Dec-Feb) low: 9°F; the coldest month, January, averages 6°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: 54 nights a year, and 28 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 6°F | 10°F | 22°F | 34°F | 47°F | 58°F | 62°F | 59°F | 50°F | 36°F | 23°F | 12°F |
Lyon County next to its neighbours
Osceola County, IA, 46 km east, gets 99 nights below 20°F to Lyon County's 96 nights. Rock County, MN, 32 km north, gets 94 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Lyon County, IA | - | 168 nights | 96 nights | 6°F |
| Rock County, MN | 32 km north | 165 nights | 94 nights | 7°F |
| Sioux County, IA | 34 km south | 155 nights | 83 nights | 9°F |
| Lincoln County, SD | 43 km west | 160 nights | 89 nights | 6°F |
| Osceola County, IA | 46 km east | 171 nights | 99 nights | 5°F |
| Nobles County, MN | 48 km northeast | 168 nights | 97 nights | 5°F |
| Minnehaha County, SD | 57 km northwest | 159 nights | 89 nights | 8°F |
Lyon County within IA
Lyon County ranks 2 of 99 IA counties for nights below 20°F. The most is Osceola County, IA at 99 nights, with a 8°F average winter low. The fewest is Des Moines County, IA: 52 nights, winter lows near 19°F. At 1,409 ft, Lyon County sits 319 ft above the state's median county elevation of 1,090 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 Rock Rapids, IA, 6 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.