Will Pipes Freeze in Mercer County, MO? 56 nights a Year
Freeze nights in Mercer County
In a normal year Mercer County, MO gets 56 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 69% of US counties.
Risk level: Severe. The risk season runs November to March, worst in January.
It depends where the pipe is
| Pipe | Freezes near | Nights a year |
|---|---|---|
| Outdoor spigot, open crawlspace | 32°F | 127 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 56 nights |
| Insulated pipe in unheated space | 10°F | 24 nights |
| Inside the heated house | 0°F | 8 nights |
Foam-sleeving a bare pipe in unheated space takes it from 56 nights of risk to 24 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 10/15, last around 04/25. For 20°F: 11/12 to 03/23.
How cold Mercer County nights get
Average winter (Dec-Feb) low: 18°F; the coldest month, January, averages 15°F overnight. 7 months normally bring at least one night below 32°F (Jan, Feb, Mar, Apr, Oct, Nov, Dec). Nights below 10°F, cold enough to freeze insulated pipe in an unheated space, come in January, February, March, November, December: 24 nights a year, and 8 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 15°F | 18°F | 29°F | 39°F | 50°F | 61°F | 65°F | 63°F | 54°F | 42°F | 30°F | 20°F |
Mercer County next to its neighbours
Harrison County, MO, 37 km west, gets 59 nights below 20°F to Mercer County's 56 nights. Grundy County, MO, 34 km south, gets 55 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Mercer County, MO | - | 127 nights | 56 nights | 15°F |
| Grundy County, MO | 34 km south | 127 nights | 55 nights | 16°F |
| Harrison County, MO | 37 km west | 132 nights | 59 nights | 15°F |
| Decatur County, IA | 40 km northwest | 138 nights | 66 nights | 14°F |
| Wayne County, IA | 41 km northeast | 141 nights | 69 nights | 13°F |
| Sullivan County, MO | 45 km southeast | 132 nights | 62 nights | 15°F |
| Putnam County, MO | 47 km east | 134 nights | 61 nights | 15°F |
Mercer County within MO
Mercer County ranks 12 of 115 MO counties for nights below 20°F. The most is Caldwell County, MO at 65 nights, with a 19°F average winter low. The fewest is Pemiscot County, MO: 14 nights, winter lows near 31°F. At 938 ft, Mercer County sits 96 ft above the state's median county elevation of 842 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 Princeton, MO, 3 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.