Ice dam risk in Niles, MI
Will your roof get ice dams in Niles, MI?
16.7 dam days a winter
High risk. On an ordinary house in Niles, conditions for an ice dam come on about 16.7 days in a normal winter, mostly in January and February.
Niles averages 63 inches of snow a year and about 55 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 Niles
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 8.5 | Moderate |
| Typical, some insulation, not air-sealed | 16.7 | High |
| Older or poorly insulated, warm attic | 26.9 | High |
Sealing and insulating a typical attic takes out about 8.2 days a winter here. It drops the risk from high to moderate. An older house with a warm attic should expect closer to 26.9 days.
What to do about ice dams in Niles
- 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.
Niles winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 22.6 | 20.4 | 7.2 |
| February | 13.6 | 14.9 | 4.9 |
| March | 6.3 | 5.2 | 1.0 |
| April | 0.8 | 0.1 | 0.0 |
| October | 0.1 | 0.0 | 0.0 |
| November | 4.6 | 2.7 | 0.4 |
| December | 14.5 | 11.9 | 3.2 |
Niles next to nearby towns
Niles ranks 55 of 90 Michigan cities here for ice-dam days, behind Sault Ste. Marie at 48.8 days.
- South Bend, IN 11 mi, 15.8 days
- Mishawaka, IN 12 mi, 15.8 days
- Elkhart, IN 18 mi, 14.8 days
- Goshen, IN 28 mi, 14.8 days
- La Porte, IN 29 mi, 15.5 days
Where these numbers come from
NOAA 1991–2020 climate normals from Niles, 1.0 miles from Niles. 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.