Ice dam risk in La Plata, MD
Ice dams in La Plata, MD: how often
2.4 dam days a winter
Low risk. On an ordinary house in La Plata, conditions for an ice dam come on about 2.4 days in a normal winter, mostly in February and January.
La Plata averages 15 inches of snow a year and about 12 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 La Plata
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 2.0 | Low |
| Typical, some insulation, not air-sealed | 2.4 | Low |
| Older or poorly insulated, warm attic | 2.9 | Low |
The attic matters less in La Plata 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 La Plata 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.
La Plata winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 5.0 | 4.0 | 0.9 |
| February | 6.2 | 4.8 | 1.0 |
| March | 1.8 | 1.0 | 0.1 |
| April | 0.1 | 0.0 | 0.0 |
| December | 2.0 | 2.1 | 0.4 |
La Plata next to nearby towns
La Plata ranks 17 of 23 Maryland cities here for ice-dam days, behind Hagerstown at 12.1 days.
- Alexandria, VA 20 mi, 1.5 days
- Washington, DC 25 mi, 2.1 days
- Falls Church, VA 26 mi, 1.1 days
- Fairfax, VA 28 mi, 3.7 days
- Hyattsville, MD 29 mi, 2.1 days
Where these numbers come from
NOAA 1991–2020 climate normals from Mechanicsville 5 NE, 13.6 miles from La Plata. 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.