Ice dam risk in Cumberland, MD

Ice dams in Cumberland, MD: how often

7.3 dam days a winter

Moderate risk. On an ordinary house in Cumberland, conditions for an ice dam come on about 7.3 days in a normal winter, mostly in January and February.

Cumberland averages 29 inches of snow a year and about 33 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 Cumberland

Attic	Dam days	Risk
Air-sealed and well insulated	5.5	Moderate
Typical, some insulation, not air-sealed	7.3	Moderate
Older or poorly insulated, warm attic	9.6	Moderate

The attic matters less in Cumberland than in colder towns: there are only 1.8 days a winter between a typical attic and a sealed one.

What to do about ice dams in Cumberland

Rake the bottom three or four feet of roof after any storm that leaves more than about six inches, from the ground with a roof rake.

Cumberland winter, month by month

Month	Snow (in)	Days on ground	Dam days
January	8.2	11.1	2.9
February	7.7	9.8	2.3
March	6.8	4.6	0.7
April	0.1	0.0	0.0
November	0.5	0.7	0.1
December	5.4	6.5	1.4

Cumberland next to nearby towns

Cumberland ranks 3 of 23 Maryland cities here for ice-dam days, behind Hagerstown at 12.1 days.

Martinsburg, WV 44 mi, 4.7 days
Winchester, VA 45 mi, 4.7 days
Johnstown, PA 47 mi, 20.5 days
Hagerstown, MD 55 mi, 12.1 days
Front Royal, VA 59 mi, 3.6 days

Where these numbers come from

NOAA 1991–2020 climate normals from Cumberland 2, 0.7 miles from Cumberland. 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 nearest weather station sits at a noticeably different elevation from Cumberland, so the snow figures may run high or low for the town itself.