Ice dam risk in Grand Junction, CO
Will your roof get ice dams in Grand Junction, CO?
6.9 dam days a winter
Moderate risk. On an ordinary house in Grand Junction, conditions for an ice dam come on about 6.9 days in a normal winter, mostly in January and December.
Grand Junction averages 18 inches of snow a year and about 24 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 Grand Junction
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 4.9 | Low |
| Typical, some insulation, not air-sealed | 6.9 | Moderate |
| Older or poorly insulated, warm attic | 9.4 | Moderate |
Sealing and insulating a typical attic takes out about 2.0 days a winter here. It drops the risk from moderate to low.
Preventing ice dams on a Grand Junction 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.
Grand Junction winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 4.5 | 11.8 | 3.6 |
| February | 2.9 | 4.0 | 0.9 |
| March | 1.8 | 0.6 | 0.1 |
| April | 0.9 | 0.1 | 0.0 |
| May | 0.1 | 0.0 | 0.0 |
| October | 0.4 | 0.2 | 0.0 |
| November | 1.9 | 0.8 | 0.2 |
| December | 5.2 | 6.9 | 2.1 |
Grand Junction next to nearby towns
Grand Junction ranks 47 of 53 Colorado cities here for ice-dam days, behind Steamboat Springs at 51.0 days.
- Fruita, CO 10 mi, 6.2 days
- Rifle, CO 53 mi, 16.6 days
- Montrose, CO 57 mi, 10.1 days
- Glenwood Springs, CO 73 mi, 15.9 days
- Vernal, UT 107 mi, 20.9 days
Where these numbers come from
NOAA 1991–2020 climate normals from Grand Junction Walker Field, 3.4 miles from Grand Junction. 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.