Will Pipes Freeze in Hamlin County, SD? 113 nights a Year
Freeze nights in Hamlin County
In a normal year Hamlin County, SD gets 113 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 96% 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 | 182 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 113 nights |
| Insulated pipe in unheated space | 10°F | 68 nights |
| Inside the heated house | 0°F | 41 nights |
Foam-sleeving a bare pipe in unheated space takes it from 113 nights of risk to 68 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 10/01, last around 05/06. For 20°F: 10/30 to 04/10.
How cold Hamlin County nights get
Average winter (Dec-Feb) low: 6°F; the coldest month, January, averages 2°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, April, November, December: 68 nights a year, and 41 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 2°F | 6°F | 19°F | 31°F | 44°F | 55°F | 59°F | 56°F | 47°F | 34°F | 21°F | 9°F |
Hamlin County next to its neighbours
Deuel County, SD, 39 km east, gets 103 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Hamlin County, SD | - | 182 nights | 113 nights | 2°F |
| Codington County, SD | 32 km north | 181 nights | 113 nights | 2°F |
| Deuel County, SD | 39 km east | 171 nights | 103 nights | 2°F |
| Kingsbury County, SD | 44 km southwest | 165 nights | 97 nights | 5°F |
| Brookings County, SD | 45 km southeast | 176 nights | 105 nights | 4°F |
| Clark County, SD | 47 km northwest | 175 nights | 107 nights | 3°F |
| Grant County, SD | 63 km northeast | 172 nights | 105 nights | 3°F |
Hamlin County within SD
Hamlin County ranks 2 of 66 SD counties for nights below 20°F. The most is Codington County, SD at 113 nights, with a 6°F average winter low. The fewest is Tripp County, SD: 75 nights, winter lows near 15°F. At 1,785 ft, Hamlin County sits close to the state's median county elevation of 1,785 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.
The dates to be done by: when freeze season starts and ends.
Where this comes from
NOAA 1991-2020 climate normals, blended from 3 nearby stations and adjusted for elevation; closest is Castlewood #2, SD, 13 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.