Ice dam risk in Sidney, OH

Will your roof get ice dams in Sidney, OH?

7.8 dam days a winter

Moderate risk. On an ordinary house in Sidney, conditions for an ice dam come on about 7.8 days in a normal winter, mostly in January and February.

Sidney 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 Sidney

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.

Preventing ice dams on a Sidney 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.

Which to spend on first: air sealing or heat cable.

Sidney 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

Sidney next to nearby towns

Sidney ranks 107 of 176 Ohio cities here for ice-dam days, behind Euclid at 24.8 days.

Piqua, OH 11 mi, 7.4 days
Troy, OH 17 mi, 7.4 days
Bellefontaine, OH 22 mi, 11.6 days
Tipp City, OH 22 mi, 7.4 days
Urbana, OH 25 mi, 7.8 days

Where these numbers come from

NOAA 1991–2020 climate normals from NEW Carlisle, 25.7 miles from Sidney. 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.

The weather station is 26 miles away, far enough that local snow can differ.