Ice dam risk in Tonawanda, NY
Will your roof get ice dams in Tonawanda, NY?
21.4 dam days a winter
High risk. On an ordinary house in Tonawanda, conditions for an ice dam come on about 21.4 days in a normal winter, mostly in January and February.
Tonawanda averages 80 inches of snow a year and about 73 days with snow on the ground. Snow that lies that long is what turns a little attic heat into a ridge of ice at the eave. 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 Tonawanda
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 11.3 | Moderate |
| Typical, some insulation, not air-sealed | 21.4 | High |
| Older or poorly insulated, warm attic | 34.0 | High |
Sealing and insulating a typical attic takes out about 10.1 days a winter here. It drops the risk from high to moderate. An older house with a warm attic should expect closer to 34.0 days.
Preventing ice dams on a Tonawanda 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.
Tonawanda winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 22.9 | 22.0 | 7.4 |
| February | 16.1 | 20.4 | 6.9 |
| March | 13.1 | 12.5 | 2.8 |
| April | 2.7 | 1.0 | 0.1 |
| October | 0.5 | 0.1 | 0.0 |
| November | 6.0 | 3.1 | 0.4 |
| December | 18.5 | 13.7 | 3.8 |
Tonawanda next to nearby towns
Tonawanda ranks 29 of 90 New York cities here for ice-dam days, behind Utica at 46.1 days.
- North Tonawanda, NY 3 mi, 21.4 days
- Kenmore, NY 3 mi, 21.4 days
- Buffalo, NY 8 mi, 21.2 days
- Niagara Falls, NY 9 mi, 18.4 days
- Depew, NY 11 mi, 21.2 days
Where these numbers come from
NOAA 1991–2020 climate normals from N Tonawanda, 3.3 miles from Tonawanda. 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.