Ice dam risk in Menomonie, WI
Will your roof get ice dams in Menomonie, WI?
32.7 dam days a winter
High risk. On an ordinary house in Menomonie, conditions for an ice dam come on about 32.7 days in a normal winter, mostly in January and February.
Menomonie averages 41 inches of snow a year and about 91 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 Menomonie
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 14.1 | Moderate |
| Typical, some insulation, not air-sealed | 32.7 | High |
| Older or poorly insulated, warm attic | 56.1 | Severe |
Sealing and insulating a typical attic takes out about 18.7 days a winter here. It drops the risk from high to moderate. An older house with a warm attic should expect closer to 56.1 days.
Preventing ice dams on a Menomonie roof
- 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.
Menomonie winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 9.7 | 26.7 | 11.3 |
| February | 11.0 | 26.6 | 10.1 |
| March | 7.3 | 16.0 | 4.1 |
| April | 2.4 | 1.3 | 0.2 |
| May | 0.5 | 0.1 | 0.0 |
| October | 0.2 | 0.0 | 0.0 |
| November | 3.5 | 3.0 | 0.7 |
| December | 6.3 | 17.1 | 6.4 |
Menomonie next to nearby towns
Menomonie ranks 14 of 98 Wisconsin cities here for ice-dam days, behind Wausau at 41.6 days.
- Eau Claire, WI 21 mi, 33.4 days
- Chippewa Falls, WI 26 mi, 36.1 days
- River Falls, WI 35 mi, 38.8 days
- New Richmond, WI 35 mi, 38.8 days
- Red Wing, MN 40 mi, 36.2 days
Where these numbers come from
NOAA 1991–2020 climate normals from Menomonie, 1.6 miles from Menomonie. 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.