Ice dam risk in Avon, OH
How often ice dams form in Avon
11.3 dam days a winter
Moderate risk. On an ordinary house in Avon, conditions for an ice dam come on about 11.3 days in a normal winter, mostly in January and February.
Avon averages 44 inches of snow a year and about 42 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 Avon
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 6.5 | Moderate |
| Typical, some insulation, not air-sealed | 11.3 | Moderate |
| Older or poorly insulated, warm attic | 17.3 | High |
Sealing and insulating a typical attic takes out about 4.8 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 17.3 days.
Preventing ice dams on a Avon 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.
Avon winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 12.9 | 15.9 | 4.9 |
| February | 10.2 | 11.7 | 3.3 |
| March | 7.6 | 4.8 | 0.9 |
| April | 1.9 | 0.4 | 0.0 |
| November | 2.2 | 1.2 | 0.1 |
| December | 8.8 | 8.1 | 2.1 |
Avon next to nearby towns
Avon ranks 91 of 176 Ohio cities here for ice-dam days, behind Euclid at 24.8 days.
- Avon Lake, OH 3 mi, 11.3 days
- Westlake, OH 4 mi, 13.8 days
- North Ridgeville, OH 4 mi, 11.3 days
- North Olmsted, OH 5 mi, 13.8 days
- Bay Village, OH 5 mi, 13.8 days
Where these numbers come from
NOAA 1991–2020 climate normals from Elyria 3 E, 5.1 miles from Avon. 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.