Ice dam risk in Lowell, IN
How often ice dams form in Lowell
12.2 dam days a winter
Moderate risk. On an ordinary house in Lowell, conditions for an ice dam come on about 12.2 days in a normal winter, mostly in January and February.
Lowell averages 30 inches of snow a year and about 39 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 Lowell
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 6.1 | Moderate |
| Typical, some insulation, not air-sealed | 12.2 | Moderate |
| Older or poorly insulated, warm attic | 19.7 | High |
Sealing and insulating a typical attic takes out about 6.0 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 19.7 days.
Preventing ice dams on a Lowell roof
- 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.
Lowell winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 9.7 | 14.7 | 5.3 |
| February | 9.3 | 10.9 | 3.5 |
| March | 3.4 | 3.6 | 0.7 |
| April | 0.3 | 0.3 | 0.0 |
| October | 0.2 | 0.0 | 0.0 |
| November | 0.9 | 0.6 | 0.1 |
| December | 5.9 | 8.5 | 2.5 |
Lowell next to nearby towns
Lowell ranks 28 of 88 Indiana cities here for ice-dam days, behind Plymouth at 15.9 days.
- Cedar Lake, IN 6 mi, 12.2 days
- Crown Point, IN 9 mi, 12.2 days
- St. John, IN 11 mi, 14.7 days
- Schererville, IN 14 mi, 14.7 days
- Merrillville, IN 14 mi, 11.9 days
Where these numbers come from
NOAA 1991–2020 climate normals from Lowell Wwtp, 1.8 miles from Lowell. 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.