Will Pipes Freeze in Poweshiek County, IA? 80 nights a Year
Freeze nights in Poweshiek County
In a normal year Poweshiek County, IA gets 80 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 October 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 | 80 nights |
| Insulated pipe in unheated space | 10°F | 40 nights |
| Inside the heated house | 0°F | 19 nights |
Foam-sleeving a bare pipe in unheated space takes it from 80 nights of risk to 40 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 10/06, last around 05/03. For 20°F: 11/03 to 04/02.
How cold Poweshiek County nights get
Average winter (Dec-Feb) low: 13°F; the coldest month, January, averages 10°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: 40 nights a year, and 19 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 10°F | 14°F | 25°F | 36°F | 48°F | 58°F | 62°F | 59°F | 51°F | 39°F | 27°F | 16°F |
Poweshiek County next to its neighbours
Iowa County, IA, 39 km east, gets 74 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Poweshiek County, IA | - | 155 nights | 80 nights | 10°F |
| Iowa County, IA | 39 km east | 151 nights | 74 nights | 10°F |
| Mahaska County, IA | 40 km south | 143 nights | 70 nights | 12°F |
| Tama County, IA | 43 km north | 152 nights | 77 nights | 10°F |
| Jasper County, IA | 44 km west | 142 nights | 71 nights | 11°F |
| Keokuk County, IA | 49 km southeast | 142 nights | 69 nights | 12°F |
| Marshall County, IA | 55 km northwest | 151 nights | 76 nights | 10°F |
Poweshiek County within IA
Poweshiek County ranks 42 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 941 ft, Poweshiek County sits 149 ft below 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.
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 Grinnell (3 mi SW), IA, 19 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.