Ice dam risk in Westerville, OH
Will your roof get ice dams in Westerville, OH?
6.6 dam days a winter
Moderate risk. On an ordinary house in Westerville, conditions for an ice dam come on about 6.6 days in a normal winter, mostly in January and February.
Westerville averages 19 inches of snow a year and about 26 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 Westerville
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 3.9 | Low |
| Typical, some insulation, not air-sealed | 6.6 | Moderate |
| Older or poorly insulated, warm attic | 10.0 | Moderate |
Sealing and insulating a typical attic takes out about 2.7 days a winter here. It drops the risk from moderate to low. An older house with a warm attic should expect closer to 10.0 days.
What to do about ice dams in Westerville
- 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.
Westerville winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 6.9 | 10.6 | 3.1 |
| February | 5.3 | 7.8 | 2.0 |
| March | 2.8 | 2.2 | 0.3 |
| April | 0.1 | 0.0 | 0.0 |
| November | 0.5 | 0.4 | 0.0 |
| December | 3.4 | 4.9 | 1.2 |
Westerville next to nearby towns
Westerville ranks 147 of 176 Ohio cities here for ice-dam days, behind Euclid at 24.8 days.
- Worthington, OH 6 mi, 6.6 days
- Gahanna, OH 6 mi, 6.7 days
- New Albany, OH 8 mi, 6.7 days
- Powell, OH 9 mi, 6.6 days
- Columbus, OH 10 mi, 6.7 days
Where these numbers come from
NOAA 1991–2020 climate normals from Westerville, 1.6 miles from Westerville. 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.