Ice dam risk in Atlantic City, NJ
How often ice dams form in Atlantic City
2.0 dam days a winter
Low risk. On an ordinary house in Atlantic City, conditions for an ice dam come on about 2.0 days in a normal winter, mostly in January and February.
Atlantic City averages 17 inches of snow a year and about 10 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 Atlantic City
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 1.6 | Low |
| Typical, some insulation, not air-sealed | 2.0 | Low |
| Older or poorly insulated, warm attic | 2.6 | Low |
The attic matters less in Atlantic City than in colder towns: there are only 0.4 days a winter between a typical attic and a sealed one.
Preventing ice dams on a Atlantic City 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.
Atlantic City winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 5.7 | 3.6 | 0.8 |
| February | 5.9 | 3.6 | 0.8 |
| March | 2.2 | 1.3 | 0.2 |
| April | 0.3 | 0.0 | 0.0 |
| November | 0.1 | 0.1 | 0.0 |
| December | 3.2 | 1.3 | 0.2 |
Atlantic City next to nearby towns
Atlantic City ranks 113 of 116 New Jersey cities here for ice-dam days, behind Hopatcong at 14.7 days.
- Pleasantville, NJ 3 mi, 2.0 days
- Somers Point, NJ 9 mi, 2.0 days
- Ocean City, NJ 11 mi, 2.0 days
- Hammonton, NJ 26 mi, 3.6 days
- Vineland, NJ 30 mi, 3.4 days
Where these numbers come from
NOAA 1991–2020 climate normals from Atlantic City International Airport, 8.0 miles from Atlantic City. 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.