Will Pipes Freeze in Mendocino County, CA? 3 nights a Year
Freeze nights in Mendocino County
In a normal year Mendocino County, CA gets 3 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 12% of US counties.
Risk level: Occasional. The risk season runs December to January, worst in December.
It depends where the pipe is
| Pipe | Freezes near | Nights a year |
|---|---|---|
| Outdoor spigot, open crawlspace | 32°F | 80 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 3 nights |
| Insulated pipe in unheated space | 10°F | none |
| Inside the heated house | 0°F | none |
Foam-sleeving a bare pipe in unheated space takes it from 3 nights of risk to none. 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 10/09, last around 05/05. For 20°F: 12/14 to 12/31.
How cold Mendocino County nights get
Average winter (Dec-Feb) low: 34°F; the coldest month, December, averages 33°F overnight. 9 months normally bring at least one night below 32°F (Jan, Feb, Mar, Apr, May, Sep, Oct, Nov, Dec).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 34°F | 35°F | 37°F | 39°F | 42°F | 46°F | 50°F | 48°F | 45°F | 39°F | 36°F | 33°F |
Mendocino County next to its neighbours
Trinity County, CA, 138 km north, gets 5 nights below 20°F to Mendocino County's 3 nights. Lake County, CA, 70 km southeast, gets 2 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Mendocino County, CA | - | 80 nights | 3 nights | 34°F |
| Lake County, CA | 70 km southeast | 64 nights | 2 nights | 33°F |
| Glenn County, CA | 91 km east | 52 nights | 1 night | 35°F |
| Colusa County, CA | 108 km east | 17 nights | under 1 night | 39°F |
| Sonoma County, CA | 110 km southeast | 18 nights | under 1 night | 40°F |
| Tehama County, CA | 129 km northeast | 19 nights | under 1 night | 38°F |
| Trinity County, CA | 138 km north | 84 nights | 5 nights | 33°F |
Mendocino County within CA
Mendocino County ranks 15 of 58 CA counties for nights below 20°F. The most is Mono County, CA at 130 nights, with a 13°F average winter low. The fewest is Orange County, CA: none, winter lows near 46°F. At 1,058 ft, Mendocino County sits 240 ft below the state's median county elevation of 1,298 ft.
What to do here
- Keep a night-of routine: drip, open cabinets, keep the heat at 55F or above.
- Foam-sleeve any pipe in the garage or crawlspace once; it is cheap and lasts years.
Whether foam sleeves are enough here: insulate or heat tape?.
Where this comes from
NOAA 1991-2020 climate normals, blended from 3 nearby stations and adjusted for elevation; closest is Willits (1 mi NE), CA, 9 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.