Ice dam risk in Cambridge, MD
Will your roof get ice dams in Cambridge, MD?
1.5 dam days a winter
Low risk. On an ordinary house in Cambridge, conditions for an ice dam come on about 1.5 days in a normal winter, mostly in February and January.
Cambridge averages 14 inches of snow a year and about 9 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 Cambridge
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 1.3 | Low |
| Typical, some insulation, not air-sealed | 1.5 | Low |
| Older or poorly insulated, warm attic | 1.8 | Low |
The attic matters less in Cambridge than in colder towns: there are only 0.2 days a winter between a typical attic and a sealed one.
Preventing ice dams on a Cambridge 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.
Cambridge winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 5.1 | 3.5 | 0.7 |
| February | 4.8 | 3.8 | 0.6 |
| March | 2.3 | 0.9 | 0.1 |
| April | 0.1 | 0.0 | 0.0 |
| December | 1.8 | 1.2 | 0.2 |
Cambridge next to nearby towns
Cambridge ranks 21 of 23 Maryland cities here for ice-dam days, behind Hagerstown at 12.1 days.
- Easton, MD 15 mi, 1.5 days
- Salisbury, MD 29 mi, 0.8 days
- Annapolis, MD 37 mi, 3.0 days
- Milford, DE 43 mi, 2.4 days
- Bowie, MD 45 mi, 3.0 days
Where these numbers come from
NOAA 1991–2020 climate normals from Royal Oak 2 SSW, 12.7 miles from Cambridge. 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.