Ice dam risk in Maple Valley, WA
Ice dams in Maple Valley, WA: how often
1.3 dam days a winter
Low risk. On an ordinary house in Maple Valley, conditions for an ice dam come on about 1.3 days in a normal winter, mostly in January and December.
Maple Valley averages 18 inches of snow a year and about 13 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 Maple Valley
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 1.1 | Low |
| Typical, some insulation, not air-sealed | 1.3 | Low |
| Older or poorly insulated, warm attic | 1.4 | Low |
The attic matters less in Maple Valley than in colder towns: there are only 0.2 days a winter between a typical attic and a sealed one.
What to do about ice dams in Maple Valley
- 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.
Maple Valley winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 6.1 | 4.2 | 0.4 |
| February | 4.0 | 2.3 | 0.2 |
| March | 2.0 | 1.5 | 0.1 |
| April | 0.4 | 0.2 | 0.0 |
| November | 0.9 | 1.7 | 0.1 |
| December | 4.1 | 3.4 | 0.4 |
Maple Valley next to nearby towns
Maple Valley ranks 15 of 91 Washington cities here for ice-dam days, behind Spokane at 13.0 days.
- Covington, WA 3 mi, 0.2 days
- Kent, WA 9 mi, 0.2 days
- Auburn, WA 9 mi, 0.2 days
- Renton, WA 11 mi, 0.2 days
- Enumclaw, WA 12 mi, 0.0 days
Where these numbers come from
NOAA 1991–2020 climate normals from Palmer 3 ESE, 9.3 miles from Maple Valley. 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.