Ice dam risk in Prineville, OR
How often ice dams form in Prineville
2.0 dam days a winter
Low risk. On an ordinary house in Prineville, conditions for an ice dam come on about 2.0 days in a normal winter, mostly in January and February.
Prineville averages 9 inches of snow a year and about 9 days with snow on the ground. Most of it comes and goes within a few days. The conditions that make a dam need all three at once: snow, cold at the eave and heat above it.
What your attic does to that number in Prineville
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 1.8 | Low |
| Typical, some insulation, not air-sealed | 2.0 | Low |
| Older or poorly insulated, warm attic | 2.4 | Low |
The attic matters less in Prineville than in colder towns: there are only 0.2 days a winter between a typical attic and a sealed one.
Preventing ice dams on a Prineville roof
- Check the gutters before the first snow and clear them, so meltwater has somewhere to go. If you see icicles thicker than a finger along the eave after a storm, that is the early sign to look at the attic.
Snowy places are not always the worst: why snowfall misleads.
Prineville winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 1.8 | 3.3 | 0.8 |
| February | 3.2 | 2.6 | 0.6 |
| March | 0.9 | 1.0 | 0.2 |
| April | 0.3 | 0.2 | 0.0 |
| November | 1.1 | 1.0 | 0.2 |
| December | 1.5 | 1.1 | 0.3 |
Prineville next to nearby towns
Prineville ranks 10 of 57 Oregon cities here for ice-dam days, behind Klamath Falls at 9.8 days.
- Redmond, OR 16 mi, 3.4 days
- Bend, OR 28 mi, 3.5 days
- The Dalles, OR 91 mi, 3.2 days
- Sweet Home, OR 91 mi, 0.0 days
- Lebanon, OR 102 mi, 0.0 days
Where these numbers come from
NOAA 1991–2020 climate normals from Prineville, 1.0 miles from Prineville. A dam day is a day with snow on the roof and freezing at the eave while heat or sun melts the snow above it. This describes a normal winter, not this one.