Ice dam risk in Urbana, OH
How often ice dams form in Urbana
7.8 dam days a winter
Moderate risk. On an ordinary house in Urbana, conditions for an ice dam come on about 7.8 days in a normal winter, mostly in January and February.
Urbana averages 19 inches of snow a year and about 31 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 Urbana
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 5.5 | Moderate |
| Typical, some insulation, not air-sealed | 7.8 | Moderate |
| Older or poorly insulated, warm attic | 10.7 | Moderate |
Sealing and insulating a typical attic takes out about 2.3 days a winter here. It does not move the risk band, but it shortens every dam.
What to do about ice dams in Urbana
- 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.
Which to spend on first: air sealing or heat cable.
Urbana winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 6.2 | 12.7 | 3.6 |
| February | 5.3 | 8.8 | 2.0 |
| March | 3.0 | 2.4 | 0.5 |
| April | 0.1 | 0.2 | 0.0 |
| November | 0.4 | 0.4 | 0.1 |
| December | 3.7 | 6.7 | 1.6 |
Urbana next to nearby towns
Urbana ranks 108 of 176 Ohio cities here for ice-dam days, behind Euclid at 24.8 days.
- Springfield, OH 13 mi, 7.8 days
- Bellefontaine, OH 18 mi, 11.6 days
- London, OH 22 mi, 10.4 days
- Marysville, OH 23 mi, 10.4 days
- Tipp City, OH 25 mi, 7.4 days
Where these numbers come from
NOAA 1991–2020 climate normals from NEW Carlisle, 19.1 miles from Urbana. 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.