Ice dam risk in La Grande, OR
Will your roof get ice dams in La Grande, OR?
6.1 dam days a winter
Moderate risk. On an ordinary house in La Grande, conditions for an ice dam come on about 6.1 days in a normal winter, mostly in January and December.
La Grande averages 9 inches of snow a year and about 26 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 La Grande
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 4.6 | Low |
| Typical, some insulation, not air-sealed | 6.1 | Moderate |
| Older or poorly insulated, warm attic | 8.1 | Moderate |
The attic matters less in La Grande than in colder towns: there are only 1.5 days a winter between a typical attic and a sealed one.
What to do about ice dams in La Grande
- 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.
La Grande winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 3.3 | 9.8 | 2.5 |
| February | 1.0 | 6.0 | 1.3 |
| March | 0.8 | 0.9 | 0.1 |
| April | 0.1 | 0.2 | 0.0 |
| November | 1.2 | 1.4 | 0.2 |
| December | 3.0 | 7.5 | 1.9 |
La Grande next to nearby towns
La Grande ranks 2 of 57 Oregon cities here for ice-dam days, behind Klamath Falls at 9.8 days.
- Baker City, OR 40 mi, 5.6 days
- Pendleton, OR 43 mi, 3.1 days
- Walla Walla, WA 53 mi, 1.6 days
- Hermiston, OR 68 mi, 2.6 days
- Kennewick, WA 80 mi, 0.3 days
Where these numbers come from
NOAA 1991–2020 climate normals from La Grande, 0.8 miles from La Grande. 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.
- Snow-on-the-ground counts come from a second, nearby station, because the closest one does not record them.