Ice dam risk in Millville, NJ
How often ice dams form in Millville
3.1 dam days a winter
Low risk. On an ordinary house in Millville, conditions for an ice dam come on about 3.1 days in a normal winter, mostly in February and January.
Millville averages 12 inches of snow a year and about 15 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 Millville
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 2.3 | Low |
| Typical, some insulation, not air-sealed | 3.1 | Low |
| Older or poorly insulated, warm attic | 4.0 | Low |
The attic matters less in Millville than in colder towns: there are only 0.8 days a winter between a typical attic and a sealed one.
Preventing ice dams on a Millville 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.
Millville winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 3.9 | 4.7 | 1.1 |
| February | 3.6 | 6.3 | 1.3 |
| March | 1.8 | 1.8 | 0.2 |
| April | 0.2 | 0.1 | 0.0 |
| November | 0.1 | 0.0 | 0.0 |
| December | 2.2 | 2.4 | 0.4 |
Millville next to nearby towns
Millville ranks 105 of 116 New Jersey cities here for ice-dam days, behind Hopatcong at 14.7 days.
- Vineland, NJ 6 mi, 3.4 days
- Bridgeton, NJ 10 mi, 3.1 days
- Glassboro, NJ 22 mi, 3.2 days
- Hammonton, NJ 24 mi, 3.6 days
- Somers Point, NJ 24 mi, 2.0 days
Where these numbers come from
NOAA 1991–2020 climate normals from Seabrook Farms, 11.1 miles from Millville. 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.