Ice dam risk in Terre Haute, IN
How often ice dams form in Terre Haute
5.5 dam days a winter
Moderate risk. On an ordinary house in Terre Haute, conditions for an ice dam come on about 5.5 days in a normal winter, mostly in January and February.
Terre Haute averages 15 inches of snow a year and about 23 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 Terre Haute
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 3.4 | Low |
| Typical, some insulation, not air-sealed | 5.5 | Moderate |
| Older or poorly insulated, warm attic | 8.2 | Moderate |
Sealing and insulating a typical attic takes out about 2.1 days a winter here. It drops the risk from moderate to low.
Preventing ice dams on a Terre Haute 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.
Which to spend on first: air sealing or heat cable.
Terre Haute winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 5.3 | 9.5 | 2.7 |
| February | 3.6 | 5.9 | 1.4 |
| March | 1.7 | 1.4 | 0.2 |
| October | 0.1 | 0.0 | 0.0 |
| November | 0.5 | 0.6 | 0.1 |
| December | 3.9 | 5.6 | 1.2 |
Terre Haute next to nearby towns
Terre Haute ranks 73 of 88 Indiana cities here for ice-dam days, behind Plymouth at 15.9 days.
- Charleston, IL 43 mi, 6.8 days
- Crawfordsville, IN 47 mi, 8.5 days
- Danville, IL 49 mi, 7.7 days
- Bloomington, IN 50 mi, 5.1 days
- Martinsville, IN 51 mi, 5.1 days
Where these numbers come from
NOAA 1991–2020 climate normals from Farmersburg TV-2, 15.3 miles from Terre Haute. 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.