Ice dam risk in Franklin Lakes, NJ

Will your roof get ice dams in Franklin Lakes, NJ?

4.7 dam days a winter

Low risk. On an ordinary house in Franklin Lakes, conditions for an ice dam come on about 4.7 days in a normal winter, mostly in February and January.

Franklin Lakes averages 28 inches of snow a year and about 24 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 Franklin Lakes

Attic	Dam days	Risk
Air-sealed and well insulated	3.4	Low
Typical, some insulation, not air-sealed	4.7	Low
Older or poorly insulated, warm attic	6.3	Moderate

The attic matters less in Franklin Lakes than in colder towns: there are only 1.3 days a winter between a typical attic and a sealed one.

What to do about ice dams in Franklin Lakes

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.

Franklin Lakes winter, month by month

Month	Snow (in)	Days on ground	Dam days
January	8.0	7.8	1.9
February	8.4	8.5	1.9
March	4.7	3.4	0.4
April	0.7	0.2	0.0
October	0.2	0.1	0.0
November	0.3	0.2	0.0
December	5.9	3.3	0.5

Franklin Lakes next to nearby towns

Franklin Lakes ranks 67 of 116 New Jersey cities here for ice-dam days, behind Hopatcong at 14.7 days.

Oakland, NJ 2 mi, 4.7 days
Waldwick, NJ 4 mi, 8.7 days
Pompton Lakes, NJ 4 mi, 5.7 days
Hawthorne, NJ 4 mi, 4.7 days
Ramsey, NJ 5 mi, 8.7 days

Where these numbers come from

NOAA 1991–2020 climate normals from Harrison, 18.1 miles from Franklin Lakes. 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.