Ice dam risk in The Dalles, OR
Ice dams in The Dalles, OR: how often
3.2 dam days a winter
Low risk. On an ordinary house in The Dalles, conditions for an ice dam come on about 3.2 days in a normal winter, mostly in January and December.
The Dalles averages 6 inches of snow a year and about 19 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 The Dalles
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 2.5 | Low |
| Typical, some insulation, not air-sealed | 3.2 | Low |
| Older or poorly insulated, warm attic | 3.9 | Low |
The attic matters less in The Dalles than in colder towns: there are only 0.7 days a winter between a typical attic and a sealed one.
What to do about ice dams in The Dalles
- 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.
The Dalles winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 1.9 | 7.7 | 1.3 |
| February | 0.8 | 2.7 | 0.5 |
| March | 0.1 | 0.4 | 0.0 |
| November | 0.7 | 1.8 | 0.2 |
| December | 2.0 | 6.5 | 1.1 |
The Dalles next to nearby towns
The Dalles ranks 7 of 57 Oregon cities here for ice-dam days, behind Klamath Falls at 9.8 days.
- Sandy, OR 56 mi, 0.2 days
- Washougal, WA 58 mi, 0.1 days
- Troutdale, OR 60 mi, 0.2 days
- Camas, WA 62 mi, 0.2 days
- Fairview, OR 62 mi, 0.2 days
Where these numbers come from
NOAA 1991–2020 climate normals from The Dalles, 2.6 miles from The Dalles. 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.
- The nearest weather station sits at a noticeably different elevation from The Dalles, so the snow figures may run high or low for the town itself.
- Snow-on-the-ground counts come from a second, nearby station, because the closest one does not record them.