Will Pipes Freeze in San Luis Obispo County, CA? under 1 night a Year
Freeze nights in San Luis Obispo County
In a normal year San Luis Obispo County, CA gets under 1 night at or below 20°F, the point where bare pipes in a garage, attic or outside wall start to freeze. That is more than 5% of US counties.
Risk level: Rare.
It depends where the pipe is
| Pipe | Freezes near | Nights a year |
|---|---|---|
| Outdoor spigot, open crawlspace | 32°F | 34 nights |
| Bare pipe in garage, attic or outside wall | 20°F | under 1 night |
| 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 under 1 night 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 11/05, last around 04/04. For 20°F: 12/15 to 12/29.
How cold San Luis Obispo County nights get
Average winter (Dec-Feb) low: 38°F; the coldest month, December, averages 37°F overnight. 6 months normally bring at least one night below 32°F (Jan, Feb, Mar, Apr, Nov, Dec).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 38°F | 39°F | 42°F | 43°F | 47°F | 51°F | 54°F | 54°F | 51°F | 46°F | 40°F | 37°F |
San Luis Obispo County next to its neighbours
Monterey County, CA, 123 km northwest, gets 1 night below 20°F to San Luis Obispo County's under 1 night. Kern County, CA, 156 km east, gets none.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| San Luis Obispo County, CA | - | 34 nights | under 1 night | 38°F |
| Kings County, CA | 95 km northeast | 27 nights | under 1 night | 37°F |
| Santa Barbara County, CA | 102 km south | 38 nights | under 1 night | 35°F |
| Monterey County, CA | 123 km northwest | 55 nights | 1 night | 35°F |
| San Benito County, CA | 148 km northwest | 59 nights | 2 nights | 35°F |
| Kern County, CA | 156 km east | 19 nights | none | 39°F |
| Ventura County, CA | 166 km southeast | 23 nights | under 1 night | 37°F |
San Luis Obispo County within CA
San Luis Obispo County ranks 29 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 1,938 ft, San Luis Obispo County sits 640 ft above the state's median county elevation of 1,298 ft.
What to do here
- Watch the forecast for a sub-threshold night.
- That night: drip the faucet on an outside wall, open the sink cabinet.
A few nights a year catches houses that were never built for it: pipes in places that rarely freeze.
Where this comes from
NOAA 1991-2020 climate normals, blended from 3 nearby stations and adjusted for elevation; closest is Paso Robles Municipal Airport, CA, 35 km away (distant match). A normal year, not tonight's forecast: check the forecast low for the night itself. How a county figure is built from stations: how the numbers are made.