Ice dam risk in Jeffersontown, KY

How often ice dams form in Jeffersontown

2.3 dam days a winter

Low risk. On an ordinary house in Jeffersontown, conditions for an ice dam come on about 2.3 days in a normal winter, mostly in January and February.

Jeffersontown averages 15 inches of snow a year and about 11 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 Jeffersontown

Attic	Dam days	Risk
Air-sealed and well insulated	1.6	Low
Typical, some insulation, not air-sealed	2.3	Low
Older or poorly insulated, warm attic	3.2	Low

The attic matters less in Jeffersontown than in colder towns: there are only 0.7 days a winter between a typical attic and a sealed one.

What to do about ice dams in Jeffersontown

Check the gutters before the first snow and clear them, so meltwater has somewhere to go. If you see icicles thicker than a finger along the eave after a storm, that is the early sign to look at the attic.

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

Jeffersontown winter, month by month

Month	Snow (in)	Days on ground	Dam days
January	4.6	4.3	1.0
February	4.7	3.5	0.7
March	2.6	0.9	0.1
April	0.1	0.0	0.0
November	0.4	0.1	0.0
December	2.7	2.5	0.5

Jeffersontown next to nearby towns

Jeffersontown ranks 18 of 42 Kentucky cities here for ice-dam days, behind Fort Thomas at 6.8 days.

Lyndon, KY 4 mi, 2.0 days
St. Matthews, KY 5 mi, 2.0 days
Louisville/Jefferson County, KY 5 mi, 2.3 days
Mount Washington, KY 11 mi, 2.3 days
Jeffersonville, IN 12 mi, 2.1 days

Where these numbers come from

NOAA 1991–2020 climate normals from Louisville Wfo, 7.5 miles from Jeffersontown. 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.