Will Pipes Freeze in Hamilton County, IA? 84 nights a Year
Freeze nights in Hamilton County
In a normal year Hamilton County, IA gets 84 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 84% 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 | 160 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 84 nights |
| Insulated pipe in unheated space | 10°F | 46 nights |
| Inside the heated house | 0°F | 23 nights |
Foam-sleeving a bare pipe in unheated space takes it from 84 nights of risk to 46 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 10/02, last around 05/03. For 20°F: 11/01 to 04/04.
How cold Hamilton County nights get
Average winter (Dec-Feb) low: 11°F; the coldest month, January, averages 7°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: 46 nights a year, and 23 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 7°F | 11°F | 24°F | 34°F | 47°F | 57°F | 61°F | 58°F | 49°F | 37°F | 24°F | 13°F |
Hamilton County next to its neighbours
Wright County, IA, 38 km north, gets 89 nights below 20°F to Hamilton County's 84 nights. Hardin County, IA, 38 km east, gets 80 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Hamilton County, IA | - | 160 nights | 84 nights | 7°F |
| Wright County, IA | 38 km north | 161 nights | 89 nights | 6°F |
| Hardin County, IA | 38 km east | 155 nights | 80 nights | 8°F |
| Webster County, IA | 39 km west | 157 nights | 83 nights | 8°F |
| Boone County, IA | 43 km southwest | 151 nights | 76 nights | 10°F |
| Story County, IA | 44 km southeast | 150 nights | 75 nights | 10°F |
| Franklin County, IA | 53 km northeast | 157 nights | 84 nights | 8°F |
Hamilton County within IA
Hamilton County ranks 23 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 1,123 ft, Hamilton County sits close to 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 Webster City, IA, 11 km away (close match). A normal year, not tonight's forecast: check the forecast low for the night itself. What a "fair" or "distant" station match means is in the method guide.