Will Pipes Freeze in Washington County, MO? 39 nights a Year
Freeze nights in Washington County
In a normal year Washington County, MO gets 39 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 55% of US counties.
Risk level: Regular. 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 | 105 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 39 nights |
| Insulated pipe in unheated space | 10°F | 13 nights |
| Inside the heated house | 0°F | 4 nights |
Foam-sleeving a bare pipe in unheated space takes it from 39 nights of risk to 13 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 10/28, last around 04/11. For 20°F: 11/26 to 03/11.
How cold Washington County nights get
Average winter (Dec-Feb) low: 24°F; the coldest month, January, averages 21°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, December: 13 nights a year, and 4 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 21°F | 25°F | 33°F | 44°F | 54°F | 63°F | 67°F | 65°F | 57°F | 46°F | 35°F | 26°F |
Washington County next to its neighbours
Crawford County, MO, 37 km west, gets 56 nights below 20°F to Washington County's 39 nights. Iron County, MO, 39 km southeast, gets 38 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Washington County, MO | - | 105 nights | 39 nights | 21°F |
| Crawford County, MO | 37 km west | 136 nights | 56 nights | 19°F |
| Iron County, MO | 39 km southeast | 107 nights | 38 nights | 22°F |
| St. Francois County, MO | 40 km east | 105 nights | 35 nights | 22°F |
| Jefferson County, MO | 47 km northeast | 104 nights | 34 nights | 22°F |
| Franklin County, MO | 55 km north | 106 nights | 35 nights | 22°F |
| Dent County, MO | 64 km southwest | 94 nights | 30 nights | 22°F |
Washington County within MO
Washington County ranks 61 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 1,025 ft, Washington County sits 183 ft above the state's median county elevation of 842 ft.
What to do here
- Insulate every pipe in unheated space before the season starts.
- Heat tape on the runs you cannot insulate well.
- Shut off and drain outdoor spigots for the season.
What insulating actually removes here, and when heat tape is needed: insulate or heat tape?.
Where this comes from
NOAA 1991-2020 climate normals, blended from 3 nearby stations and adjusted for elevation; closest is Potosi (4 mi SW), MO, 7 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.