Ice dam risk in Appleton, WI
How often ice dams form in Appleton
30.0 dam days a winter
High risk. On an ordinary house in Appleton, conditions for an ice dam come on about 30.0 days in a normal winter, mostly in January and February.
Appleton averages 49 inches of snow a year and about 83 days with snow on the ground. Snow that lies that long is what turns a little attic heat into a ridge of ice at the eave. 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 Appleton
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 12.3 | Moderate |
| Typical, some insulation, not air-sealed | 30.0 | High |
| Older or poorly insulated, warm attic | 52.0 | Severe |
Sealing and insulating a typical attic takes out about 17.6 days a winter here. It drops the risk from high to moderate. An older house with a warm attic should expect closer to 52.0 days.
What to do about ice dams in Appleton
- Air-seal the attic floor: the gaps around the hatch, light fixtures, plumbing stacks and the top plates of interior walls. This is the fix that removes the cause, and it usually costs less than a season of contractor ice removal.
- Rake the bottom three or four feet of roof after any storm that leaves more than about six inches, from the ground with a roof rake.
- At the next reroof, ask for ice-and-water membrane under the shingles from the eave to at least 24 inches inside the wall line. It does not stop a dam; it stops the leak when one forms.
Which to spend on first: air sealing or heat cable.
Appleton winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 12.6 | 24.5 | 10.4 |
| February | 11.2 | 23.6 | 9.2 |
| March | 7.2 | 13.1 | 3.5 |
| April | 4.0 | 2.1 | 0.2 |
| May | 0.1 | 0.0 | 0.0 |
| October | 0.3 | 0.1 | 0.0 |
| November | 2.4 | 2.9 | 0.6 |
| December | 11.6 | 16.4 | 6.1 |
Appleton next to nearby towns
Appleton ranks 18 of 98 Wisconsin cities here for ice-dam days, behind Wausau at 41.6 days.
- Little Chute, WI 3 mi, 30.0 days
- Menasha, WI 5 mi, 30.0 days
- Fox Crossing, WI 6 mi, 30.0 days
- Kaukauna, WI 6 mi, 30.0 days
- Harrison, WI 8 mi, 30.0 days
Where these numbers come from
NOAA 1991–2020 climate normals from Appleton, 2.5 miles from Appleton. 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.