Ice dam risk in Sumner, WA
Ice dams in Sumner, WA: how often
0.5 dam days a winter
Almost never. An ordinary house in Sumner sees 0.5 days a winter when an ice dam can form, because snow rarely stays on a roof long enough below freezing.
Sumner averages 6 inches of snow a year and about 5 days with snow on the ground. Too little lies on the roof for long. The conditions that make a dam need all three at once: snow, cold at the eave and heat above it.
Do you need to do anything in Sumner?
- Nothing for ice dams. If you are buying here and an inspector mentions water at the eaves, ask what they saw: it is far more likely a gutter, flashing or drip-edge problem than ice.
Snowy places are not always the worst: why snowfall misleads.
Sumner winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 1.5 | 1.5 | 0.2 |
| February | 0.5 | 0.4 | 0.0 |
| March | 0.6 | 0.5 | 0.0 |
| November | 1.5 | 1.0 | 0.1 |
| December | 1.5 | 1.6 | 0.2 |
Sumner next to nearby towns
Sumner ranks 24 of 91 Washington cities here for ice-dam days, behind Spokane at 13.0 days.
- Edgewood, WA 2 mi, 0.5 days
- Bonney Lake, WA 4 mi, 0.5 days
- Puyallup, WA 4 mi, 0.5 days
- Fife, WA 5 mi, 0.5 days
- Auburn, WA 5 mi, 0.2 days
Where these numbers come from
NOAA 1991–2020 climate normals from Mcmillin Rsvr, 6.4 miles from Sumner. 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.