Will Pipes Freeze in Mariposa County, CA? 5 nights a Year
Freeze nights in Mariposa County
In a normal year Mariposa County, CA gets 5 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 17% of US counties.
Risk level: Occasional. The risk season runs December to February, worst in January.
It depends where the pipe is
| Pipe | Freezes near | Nights a year |
|---|---|---|
| Outdoor spigot, open crawlspace | 32°F | 94 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 5 nights |
| Insulated pipe in unheated space | 10°F | under 1 night |
| Inside the heated house | 0°F | none |
Foam-sleeving a bare pipe in unheated space takes it from 5 nights of risk to under 1 night. 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 11/02, last around 04/22. For 20°F: 12/25 to 01/23.
How cold Mariposa County nights get
Average winter (Dec-Feb) low: 31°F; the coldest month, January, averages 31°F overnight. 8 months normally bring at least one night below 32°F (Jan, Feb, Mar, Apr, May, Oct, Nov, Dec).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 31°F | 31°F | 35°F | 38°F | 44°F | 51°F | 57°F | 56°F | 51°F | 42°F | 35°F | 31°F |
Mariposa County next to its neighbours
Tuolumne County, CA, 50 km north, gets 11 nights below 20°F to Mariposa County's 5 nights. Madera County, CA, 43 km south, gets 1 night.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Mariposa County, CA | - | 94 nights | 5 nights | 31°F |
| Madera County, CA | 43 km south | 41 nights | 1 night | 36°F |
| Tuolumne County, CA | 50 km north | 91 nights | 11 nights | 31°F |
| Merced County, CA | 83 km southwest | 33 nights | under 1 night | 37°F |
| Calaveras County, CA | 89 km northwest | 35 nights | under 1 night | 36°F |
| Fresno County, CA | 93 km south | 12 nights | none | 39°F |
| Stanislaus County, CA | 96 km west | 12 nights | none | 39°F |
Mariposa County within CA
Mariposa County ranks 13 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 3,046 ft, Mariposa County sits 1,747 ft above 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.
Few hard nights means pipes are rarely built for them; see freezes in warm places.
Where this comes from
NOAA 1991-2020 climate normals, blended from 3 nearby stations and adjusted for elevation; closest is Groveland 2, CA, 41 km away (fair 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.