Ice dam risk in Adrian, MI
How often ice dams form in Adrian
14.9 dam days a winter
Moderate risk. On an ordinary house in Adrian, conditions for an ice dam come on about 14.9 days in a normal winter, mostly in January and February.
Adrian averages 26 inches of snow a year and about 47 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 Adrian
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 7.7 | Moderate |
| Typical, some insulation, not air-sealed | 14.9 | Moderate |
| Older or poorly insulated, warm attic | 23.8 | High |
Sealing and insulating a typical attic takes out about 7.1 days a winter here. It does not move the risk band, but it shortens every dam. An older house with a warm attic should expect closer to 23.8 days.
Preventing ice dams on a Adrian 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.
Which to spend on first: air sealing or heat cable.
Adrian winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 9.0 | 16.7 | 6.0 |
| February | 5.8 | 14.2 | 4.7 |
| March | 4.1 | 5.5 | 1.2 |
| April | 1.0 | 0.4 | 0.0 |
| November | 1.3 | 1.1 | 0.2 |
| December | 4.8 | 9.4 | 2.8 |
Adrian next to nearby towns
Adrian ranks 68 of 90 Michigan cities here for ice-dam days, behind Sault Ste. Marie at 48.8 days.
- Sylvania, OH 22 mi, 11.9 days
- Toledo, OH 29 mi, 11.9 days
- Maumee, OH 30 mi, 11.9 days
- Jackson, MI 30 mi, 18.6 days
- Ann Arbor, MI 31 mi, 20.5 days
Where these numbers come from
NOAA 1991–2020 climate normals from Adrian 2 NNE, 1.9 miles from Adrian. 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.