Ice dam risk in Caldwell, ID
How often ice dams form in Caldwell
2.9 dam days a winter
Low risk. On an ordinary house in Caldwell, conditions for an ice dam come on about 2.9 days in a normal winter, mostly in January and December.
Caldwell averages 10 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 Caldwell
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 2.3 | Low |
| Typical, some insulation, not air-sealed | 2.9 | Low |
| Older or poorly insulated, warm attic | 3.8 | Low |
The attic matters less in Caldwell than in colder towns: there are only 0.6 days a winter between a typical attic and a sealed one.
Preventing ice dams on a Caldwell 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.
Caldwell winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 3.4 | 4.8 | 1.3 |
| February | 1.4 | 2.2 | 0.5 |
| March | 0.2 | 0.1 | 0.0 |
| November | 0.5 | 1.0 | 0.2 |
| December | 4.2 | 3.9 | 1.0 |
Caldwell next to nearby towns
Caldwell ranks 22 of 26 Idaho cities here for ice-dam days, behind Rexburg at 42.8 days.
- Middleton, ID 5 mi, 2.9 days
- Nampa, ID 6 mi, 2.9 days
- Star, ID 9 mi, 2.9 days
- Eagle, ID 13 mi, 2.9 days
- Meridian, ID 13 mi, 4.0 days
Where these numbers come from
NOAA 1991–2020 climate normals from Nampa Sugar Factory, 5.1 miles from Caldwell. 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.