Ice dam risk in Coldwater, MI
Ice dams in Coldwater, MI: how often
17.3 dam days a winter
High risk. On an ordinary house in Coldwater, conditions for an ice dam come on about 17.3 days in a normal winter, mostly in January and February.
Coldwater averages 43 inches of snow a year and about 53 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 Coldwater
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 7.9 | Moderate |
| Typical, some insulation, not air-sealed | 17.3 | High |
| Older or poorly insulated, warm attic | 29.1 | High |
Sealing and insulating a typical attic takes out about 9.4 days a winter here. It drops the risk from high to moderate. An older house with a warm attic should expect closer to 29.1 days.
Preventing ice dams on a Coldwater 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.
Which to spend on first: air sealing or heat cable.
Coldwater winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 13.1 | 18.4 | 7.0 |
| February | 10.7 | 15.8 | 5.5 |
| March | 4.9 | 6.0 | 1.3 |
| April | 1.1 | 0.4 | 0.0 |
| October | 0.1 | 0.0 | 0.0 |
| November | 3.6 | 2.4 | 0.4 |
| December | 9.2 | 10.0 | 3.2 |
Coldwater next to nearby towns
Coldwater ranks 54 of 90 Michigan cities here for ice-dam days, behind Sault Ste. Marie at 48.8 days.
- Sturgis, MI 24 mi, 18.7 days
- Battle Creek, MI 27 mi, 19.4 days
- Portage, MI 35 mi, 18.7 days
- Jackson, MI 37 mi, 18.6 days
- Kendallville, IN 37 mi, 13.4 days
Where these numbers come from
NOAA 1991–2020 climate normals from Coldwater St School, 1.2 miles from Coldwater. 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.