Ice dam risk in Cloquet, MN
How often ice dams form in Cloquet
52.2 dam days a winter
Severe risk. On an ordinary house in Cloquet, conditions for an ice dam come on about 52.2 days in a normal winter, mostly in January and February.
Cloquet averages 71 inches of snow a year and about 138 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 Cloquet
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 20.6 | High |
| Typical, some insulation, not air-sealed | 52.2 | Severe |
| Older or poorly insulated, warm attic | 91.7 | Severe |
Sealing and insulating a typical attic takes out about 31.6 days a winter here. It drops the risk from severe to high. An older house with a warm attic should expect closer to 91.7 days.
Preventing ice dams on a Cloquet 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.
- Heat cable is worth pricing here even on a sealed house, along the eave and in the gutters and downspouts it drains into.
Running 60 feet of 5 W/ft cable whenever snow lies below freezing would use about 569 kWh a winter in Cloquet, roughly $97 at 17 cents a kWh.
Which to spend on first: air sealing or heat cable.
Cloquet winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 13.5 | 30.6 | 14.1 |
| February | 13.5 | 28.5 | 11.8 |
| March | 10.3 | 27.2 | 8.2 |
| April | 6.4 | 7.8 | 1.5 |
| May | 0.3 | 0.1 | 0.0 |
| October | 1.8 | 1.3 | 0.2 |
| November | 9.6 | 14.4 | 4.3 |
| December | 15.9 | 28.1 | 12.1 |
Cloquet next to nearby towns
Cloquet ranks 2 of 103 Minnesota cities here for ice-dam days, behind Hermantown at 52.9 days.
- Hermantown, MN 13 mi, 52.9 days
- Duluth, MN 18 mi, 38.4 days
- Superior, WI 20 mi, 38.4 days
- Hibbing, MN 51 mi, 49.9 days
- Grand Rapids, MN 60 mi, 49.9 days
Where these numbers come from
NOAA 1991–2020 climate normals from Cloquet, 1.7 miles from Cloquet. 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.