Ice dam risk in Morristown, TN

Will your roof get ice dams in Morristown, TN?

0.8 dam days a winter

Almost never. An ordinary house in Morristown sees 0.8 days a winter when an ice dam can form, because snow rarely stays on a roof long enough below freezing.

Morristown averages 9 inches of snow a year and about 5 days with snow on the ground. Too little lies on the roof for long. 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 Morristown

Attic	Dam days	Risk
Air-sealed and well insulated	0.7	Very unlikely
Typical, some insulation, not air-sealed	0.8	Very unlikely
Older or poorly insulated, warm attic	1.0	Very unlikely

The attic matters less in Morristown than in colder towns: there are only 0.1 days a winter between a typical attic and a sealed one.

Do you need to do anything in Morristown?

Nothing for ice dams. If you are buying here and an inspector mentions water at the eaves, ask what they saw: it is far more likely a gutter, flashing or drip-edge problem than ice.

Snowy places are not always the worst: why snowfall misleads.

Morristown winter, month by month

Month	Snow (in)	Days on ground	Dam days
January	2.1	2.5	0.5
February	2.9	1.2	0.2
March	2.0	0.1	0.0
November	0.2	0.1	0.0
December	1.6	0.7	0.1

Morristown next to nearby towns

Morristown ranks 9 of 65 Tennessee cities here for ice-dam days, behind Crossville at 2.6 days.

Sevierville, TN 27 mi, 0.3 days
Greeneville, TN 27 mi, 1.2 days
Knoxville, TN 40 mi, 0.5 days
Alcoa, TN 46 mi, 0.5 days
Clinton, TN 47 mi, 0.6 days

Where these numbers come from

NOAA 1991–2020 climate normals from Morristown Radio Wcrk, 1.8 miles from Morristown. 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.

Snow-on-the-ground counts come from a second, nearby station, because the closest one does not record them.