Ice dam risk in Ridgefield, NJ

Will your roof get ice dams in Ridgefield, NJ?

4.3 dam days a winter

Low risk. On an ordinary house in Ridgefield, conditions for an ice dam come on about 4.3 days in a normal winter, mostly in February and January.

Ridgefield averages 30 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 Ridgefield

Attic	Dam days	Risk
Air-sealed and well insulated	2.8	Low
Typical, some insulation, not air-sealed	4.3	Low
Older or poorly insulated, warm attic	6.2	Moderate

The attic matters less in Ridgefield than in colder towns: there are only 1.5 days a winter between a typical attic and a sealed one.

Preventing ice dams on a Ridgefield roof

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.

Ridgefield winter, month by month

Month	Snow (in)	Days on ground	Dam days
January	8.8	7.9	1.8
February	10.1	9.1	1.8
March	5.0	4.0	0.4
April	0.4	0.1	0.0
October	0.1	0.0	0.0
November	0.5	0.2	0.0
December	4.9	2.9	0.4

Ridgefield next to nearby towns

Ridgefield ranks 88 of 116 New Jersey cities here for ice-dam days, behind Hopatcong at 14.7 days.

Fairview, NJ 1 mi, 4.3 days
Little Ferry, NJ 1 mi, 4.3 days
Palisades Park, NJ 1 mi, 4.3 days
Ridgefield Park, NJ 2 mi, 4.3 days
Cliffside Park, NJ 2 mi, 4.3 days

Where these numbers come from

NOAA 1991–2020 climate normals from Ny City Cntrl Park, 4.4 miles from Ridgefield. 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.