Ice dam risk in Valparaiso, IN
Will your roof get ice dams in Valparaiso, IN?
14.6 dam days a winter
Moderate risk. On an ordinary house in Valparaiso, conditions for an ice dam come on about 14.6 days in a normal winter, mostly in January and February.
Valparaiso averages 40 inches of snow a year and about 49 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 Valparaiso
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 7.2 | Moderate |
| Typical, some insulation, not air-sealed | 14.6 | Moderate |
| Older or poorly insulated, warm attic | 23.8 | High |
Sealing and insulating a typical attic takes out about 7.4 days a winter here. It does not move the risk band, but it shortens every dam. An older house with a warm attic should expect closer to 23.8 days.
What to do about ice dams in Valparaiso
- Air-seal the attic floor: the gaps around the hatch, light fixtures, plumbing stacks and the top plates of interior walls. This is the fix that removes the cause, and it usually costs less than a season of contractor ice removal.
- 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.
Which to spend on first: air sealing or heat cable.
Valparaiso winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 14.6 | 17.6 | 6.5 |
| February | 5.5 | 14.1 | 4.0 |
| March | 6.7 | 5.4 | 1.1 |
| April | 1.2 | 0.4 | 0.0 |
| October | 0.3 | 0.0 | 0.0 |
| November | 2.3 | 1.9 | 0.3 |
| December | 9.4 | 9.1 | 2.7 |
Valparaiso next to nearby towns
Valparaiso ranks 18 of 88 Indiana cities here for ice-dam days, behind Plymouth at 15.9 days.
- Chesterton, IN 8 mi, 14.1 days
- Portage, IN 10 mi, 14.1 days
- Hobart, IN 12 mi, 14.0 days
- Lake Station, IN 12 mi, 14.1 days
- Merrillville, IN 14 mi, 11.9 days
Where these numbers come from
NOAA 1991–2020 climate normals from Valparaiso Wtr Wks, 2.3 miles from Valparaiso. 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.
- Snow-on-the-ground counts come from a second, nearby station, because the closest one does not record them.