Will Pipes Freeze in Umatilla County, OR? 18 nights a Year
Freeze nights in Umatilla County
In a normal year Umatilla County, OR gets 18 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 35% of US counties.
Risk level: Regular. The risk season runs October to March, worst in December.
It depends where the pipe is
| Pipe | Freezes near | Nights a year |
|---|---|---|
| Outdoor spigot, open crawlspace | 32°F | 103 nights |
| Bare pipe in garage, attic or outside wall | 20°F | 18 nights |
| Insulated pipe in unheated space | 10°F | 5 nights |
| Inside the heated house | 0°F | 1 night |
Foam-sleeving a bare pipe in unheated space takes it from 18 nights of risk to 5 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 10/22, last around 04/14. For 20°F: 11/25 to 02/15.
How cold Umatilla County nights get
Average winter (Dec-Feb) low: 28°F; the coldest month, December, averages 27°F overnight. 9 months normally bring at least one night below 32°F (Jan, Feb, Mar, Apr, May, Sep, Oct, Nov, Dec). Nights below 10°F, cold enough to freeze insulated pipe in an unheated space, come in January, February, November, December: 5 nights a year, and 1 night below zero.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 28°F | 29°F | 33°F | 38°F | 45°F | 50°F | 56°F | 55°F | 48°F | 39°F | 32°F | 27°F |
Umatilla County next to its neighbours
Union County, OR, 66 km southeast, gets 30 nights below 20°F to Umatilla County's 18 nights. Walla Walla County, WA, 76 km north, gets 14 nights.
| County | Distance | Below 32°F | Below 20°F | Jan low |
|---|---|---|---|---|
| Umatilla County, OR | - | 103 nights | 18 nights | 28°F |
| Union County, OR | 66 km southeast | 137 nights | 30 nights | 25°F |
| Morrow County, OR | 70 km west | 107 nights | 18 nights | 28°F |
| Walla Walla County, WA | 76 km north | 83 nights | 14 nights | 30°F |
| Benton County, WA | 93 km northwest | 103 nights | 19 nights | 27°F |
| Columbia County, WA | 101 km northeast | 111 nights | 20 nights | 27°F |
| Franklin County, WA | 106 km north | 115 nights | 19 nights | 26°F |
Umatilla County within OR
Umatilla County ranks 16 of 36 OR counties for nights below 20°F. The most is Baker County, OR at 76 nights, with a 20°F average winter low. The fewest is Lincoln County, OR: under 1 night, winter lows near 40°F. At 1,472 ft, Umatilla County sits 545 ft below the state's median county elevation of 2,017 ft.
What to do here
- Insulate every pipe in unheated space before the season starts.
- Heat tape on the runs you cannot insulate well.
- Shut off and drain outdoor spigots for the season.
What insulating actually removes here, and when heat tape is needed: insulate or heat tape?.
Where this comes from
NOAA 1991-2020 climate normals, blended from 3 nearby stations and adjusted for elevation; closest is Pendleton Weather Office, OR, 14 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.