Will Pipes Freeze in Lassen County, CA? 49 nights a Year
Freeze nights in Lassen County
In a normal year Lassen County, CA gets 49 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 63% of US counties.
Risk level: Severe. The risk season runs October to April, worst in December.
It depends where the pipe is
| Pipe | Freezes near | Nights a year |
|---|---|---|
| Outdoor spigot, open crawlspace | 32°F | 176 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 49 nights |
| Insulated pipe in unheated space | 10°F | 11 nights |
| Inside the heated house | 0°F | 2 nights |
Foam-sleeving a bare pipe in unheated space takes it from 49 nights of risk to 11 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 09/18, last around 06/14. For 20°F: 10/30 to 04/18.
How cold Lassen County nights get
Average winter (Dec-Feb) low: 22°F; the coldest month, December, averages 21°F overnight. 10 months normally bring at least one night below 32°F (Jan, Feb, Mar, Apr, May, Jun, Sep, Oct, Nov, Dec). Nights below 10°F, cold enough to freeze insulated pipe in an unheated space, come in January, February, November, December: 11 nights a year, and 2 nights below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 22°F | 23°F | 27°F | 31°F | 37°F | 43°F | 49°F | 48°F | 42°F | 33°F | 27°F | 21°F |
Lassen County next to its neighbours
Washoe County, NV, 81 km east, gets 54 nights below 20°F to Lassen County's 49 nights. Plumas County, CA, 82 km south, gets 35 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Lassen County, CA | - | 176 nights | 49 nights | 22°F |
| Washoe County, NV | 81 km east | 164 nights | 54 nights | 21°F |
| Plumas County, CA | 82 km south | 166 nights | 35 nights | 24°F |
| Modoc County, CA | 98 km north | 198 nights | 70 nights | 21°F |
| Shasta County, CA | 120 km west | 17 nights | under 1 night | 39°F |
| Sierra County, CA | 127 km south | 220 nights | 72 nights | 20°F |
| Butte County, CA | 143 km southwest | 22 nights | under 1 night | 39°F |
Lassen County within CA
Lassen County ranks 5 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 7,048 ft, Lassen County sits 5,749 ft above the state's median county elevation of 1,298 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 Jess Valley, CA, 67 km away (distant 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.