Ice dam risk in Racine, WI
Will your roof get ice dams in Racine, WI?
16.4 dam days a winter
High risk. On an ordinary house in Racine, conditions for an ice dam come on about 16.4 days in a normal winter, mostly in January and February.
Racine averages 41 inches of snow a year and about 52 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 Racine
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 7.3 | Moderate |
| Typical, some insulation, not air-sealed | 16.4 | High |
| Older or poorly insulated, warm attic | 27.7 | High |
Sealing and insulating a typical attic takes out about 9.1 days a winter here. It drops the risk from high to moderate. An older house with a warm attic should expect closer to 27.7 days.
What to do about ice dams in Racine
- 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.
Racine winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 13.3 | 18.7 | 7.0 |
| February | 10.9 | 15.1 | 5.1 |
| March | 5.5 | 6.4 | 1.3 |
| April | 1.0 | 0.6 | 0.0 |
| November | 1.9 | 1.7 | 0.2 |
| December | 8.4 | 9.4 | 2.8 |
Racine next to nearby towns
Racine ranks 94 of 98 Wisconsin cities here for ice-dam days, behind Wausau at 41.6 days.
- Mount Pleasant, WI 4 mi, 16.4 days
- Caledonia, WI 6 mi, 16.4 days
- Kenosha, WI 10 mi, 13.7 days
- Oak Creek, WI 11 mi, 18.4 days
- South Milwaukee, WI 13 mi, 18.4 days
Where these numbers come from
NOAA 1991–2020 climate normals from Racine Wwtp, 2.1 miles from Racine. 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.