Ice dam risk in Athens, OH
How often ice dams form in Athens
5.2 dam days a winter
Moderate risk. On an ordinary house in Athens, conditions for an ice dam come on about 5.2 days in a normal winter, mostly in January and February.
Athens averages 18 inches of snow a year and about 21 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 Athens
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 3.4 | Low |
| Typical, some insulation, not air-sealed | 5.2 | Moderate |
| Older or poorly insulated, warm attic | 7.5 | Moderate |
The attic matters less in Athens than in colder towns: there are only 1.8 days a winter between a typical attic and a sealed one.
Preventing ice dams on a Athens roof
- Check the gutters before the first snow and clear them, so meltwater has somewhere to go. If you see icicles thicker than a finger along the eave after a storm, that is the early sign to look at the attic.
Snowy places are not always the worst: why snowfall misleads.
Athens winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 5.8 | 8.6 | 2.5 |
| February | 5.9 | 6.5 | 1.6 |
| March | 2.3 | 1.9 | 0.3 |
| April | 0.1 | 0.1 | 0.0 |
| November | 0.5 | 0.4 | 0.1 |
| December | 3.0 | 3.2 | 0.8 |
Athens next to nearby towns
Athens ranks 169 of 176 Ohio cities here for ice-dam days, behind Euclid at 24.8 days.
- Parkersburg, WV 30 mi, 3.5 days
- Vienna, WV 30 mi, 3.5 days
- Marietta, OH 36 mi, 3.7 days
- Lancaster, OH 39 mi, 5.2 days
- Zanesville, OH 44 mi, 8.0 days
Where these numbers come from
NOAA 1991–2020 climate normals from Athens Ou, 0.3 miles from Athens. 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.