Ice dam risk in St. Cloud, MN
Ice dams in St. Cloud, MN: how often
38.6 dam days a winter
Severe risk. On an ordinary house in St. Cloud, conditions for an ice dam come on about 38.6 days in a normal winter, mostly in January and February.
St. Cloud averages 48 inches of snow a year and about 101 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 St. Cloud
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 14.6 | Moderate |
| Typical, some insulation, not air-sealed | 38.6 | Severe |
| Older or poorly insulated, warm attic | 68.6 | Severe |
Sealing and insulating a typical attic takes out about 24.0 days a winter here. It drops the risk from severe to moderate. An older house with a warm attic should expect closer to 68.6 days.
What to do about ice dams in St. Cloud
- 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.
St. Cloud winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 8.8 | 27.8 | 12.6 |
| February | 8.9 | 24.8 | 10.2 |
| March | 8.2 | 16.8 | 4.7 |
| April | 4.7 | 3.7 | 0.5 |
| May | 0.1 | 0.0 | 0.0 |
| October | 1.0 | 0.5 | 0.1 |
| November | 6.9 | 6.7 | 1.9 |
| December | 9.3 | 21.0 | 8.6 |
St. Cloud next to nearby towns
St. Cloud ranks 24 of 103 Minnesota cities here for ice-dam days, behind Hermantown at 52.9 days.
- Sauk Rapids, MN 5 mi, 38.6 days
- Sartell, MN 7 mi, 39.1 days
- Big Lake, MN 24 mi, 36.5 days
- Monticello, MN 25 mi, 36.4 days
- Buffalo, MN 28 mi, 36.4 days
Where these numbers come from
NOAA 1991–2020 climate normals from St Cloud Regional Airport, 5.9 miles from St. Cloud. 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.