Ice dam risk in Hyrum, UT
Ice dams in Hyrum, UT: how often
24.8 dam days a winter
High risk. On an ordinary house in Hyrum, conditions for an ice dam come on about 24.8 days in a normal winter, mostly in January and December.
Hyrum averages 52 inches of snow a year and about 78 days with snow on the ground. Snow that lies that long is what turns a little attic heat into a ridge of ice at the eave. 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 Hyrum
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 14.2 | Moderate |
| Typical, some insulation, not air-sealed | 24.8 | High |
| Older or poorly insulated, warm attic | 38.0 | Severe |
Sealing and insulating a typical attic takes out about 10.6 days a winter here. It drops the risk from high to moderate. An older house with a warm attic should expect closer to 38.0 days.
What to do about ice dams in Hyrum
- 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.
- At the next reroof, ask for ice-and-water membrane under the shingles from the eave to at least 24 inches inside the wall line. It does not stop a dam; it stops the leak when one forms.
Which to spend on first: air sealing or heat cable.
Hyrum winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 12.5 | 23.7 | 8.6 |
| February | 11.7 | 20.2 | 6.3 |
| March | 5.9 | 8.2 | 1.7 |
| April | 2.5 | 1.1 | 0.1 |
| May | 0.1 | 0.0 | 0.0 |
| October | 1.0 | 0.5 | 0.1 |
| November | 4.7 | 4.5 | 1.1 |
| December | 13.2 | 19.8 | 6.9 |
Hyrum next to nearby towns
Hyrum ranks 4 of 67 Utah cities here for ice-dam days, behind Ogden at 37.2 days.
- Logan, UT 7 mi, 23.3 days
- North Logan, UT 10 mi, 23.3 days
- Brigham City, UT 14 mi, 14.3 days
- Smithfield, UT 14 mi, 23.2 days
- Tremonton, UT 19 mi, 15.7 days
Where these numbers come from
NOAA 1991–2020 climate normals from Logan 5 SW Exp Farm, 3.3 miles from Hyrum. 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.