Will Pipes Freeze in Black Hawk County, IA? 77 nights a Year
Freeze nights in Black Hawk County
In a normal year Black Hawk County, IA gets 77 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 80% 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 | 150 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 77 nights |
| Insulated pipe in unheated space | 10°F | 41 nights |
| Inside the heated house | 0°F | 20 nights |
Foam-sleeving a bare pipe in unheated space takes it from 77 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 10/10, last around 04/27. For 20°F: 11/07 to 03/29.
How cold Black Hawk County nights get
Average winter (Dec-Feb) low: 14°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: 41 nights a year, and 20 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 10°F | 15°F | 26°F | 38°F | 50°F | 60°F | 64°F | 61°F | 52°F | 40°F | 27°F | 17°F |
Black Hawk County next to its neighbours
Bremer County, IA, 34 km north, gets 83 nights below 20°F to Black Hawk County's 77 nights. Benton County, IA, 47 km southeast, gets 72 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Black Hawk County, IA | - | 150 nights | 77 nights | 10°F |
| Bremer County, IA | 34 km north | 157 nights | 83 nights | 7°F |
| Buchanan County, IA | 38 km east | 152 nights | 78 nights | 8°F |
| Grundy County, IA | 40 km west | 154 nights | 81 nights | 9°F |
| Benton County, IA | 47 km southeast | 146 nights | 72 nights | 9°F |
| Tama County, IA | 48 km southwest | 152 nights | 77 nights | 10°F |
| Butler County, IA | 49 km northwest | 150 nights | 78 nights | 8°F |
Black Hawk County within IA
Black Hawk County ranks 50 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 838 ft, Black Hawk County sits 251 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 Waterloo Municipal Airport, IA, 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.