Will Pipes Freeze in Snohomish County, WA? 6 nights a Year
Freeze nights in Snohomish County
In a normal year Snohomish County, WA gets 6 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 20% of US counties.
Risk level: Occasional. The risk season runs November to February, worst in January.
It depends where the pipe is
| Pipe | Freezes near | Nights a year |
|---|---|---|
| Outdoor spigot, open crawlspace | 32°F | 82 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 6 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 6 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 11/10, last around 04/13. For 20°F: 12/24 to 01/07.
How cold Snohomish County nights get
Average winter (Dec-Feb) low: 32°F; the coldest month, December, averages 32°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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 32°F | 32°F | 34°F | 38°F | 44°F | 49°F | 53°F | 53°F | 49°F | 42°F | 36°F | 32°F |
Snohomish County next to its neighbours
Skagit County, WA, 49 km north, gets 7 nights below 20°F to Snohomish County's 6 nights. King County, WA, 63 km south, gets 4 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Snohomish County, WA | - | 82 nights | 6 nights | 32°F |
| Skagit County, WA | 49 km north | 82 nights | 7 nights | 31°F |
| King County, WA | 63 km south | 78 nights | 4 nights | 33°F |
| Island County, WA | 68 km west | 28 nights | 1 night | 37°F |
| Kitsap County, WA | 81 km southwest | 46 nights | 2 nights | 35°F |
| Whatcom County, WA | 88 km north | 73 nights | 6 nights | 31°F |
| Chelan County, WA | 88 km east | 185 nights | 60 nights | 18°F |
Snohomish County within WA
Snohomish County ranks 24 of 39 WA counties for nights below 20°F. The most is Ferry County, WA at 62 nights, with a 18°F average winter low. The fewest is Island County, WA: 1 night, winter lows near 37°F. At 4,839 ft, Snohomish County sits 3,219 ft above the state's median county elevation of 1,620 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.
Which pipe gets which threshold: the 32, 20, 10 and 0 rule.
Where this comes from
NOAA 1991-2020 climate normals, blended from 3 nearby stations and adjusted for elevation; closest is Tolt S Fk Rsvr, WA, 40 km away (distant 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.