Ice dam risk in Marshall, MO
Will your roof get ice dams in Marshall, MO?
2.0 dam days a winter
Low risk. On an ordinary house in Marshall, conditions for an ice dam come on about 2.0 days in a normal winter, mostly in January and February.
Marshall averages 8 inches of snow a year and about 8 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 Marshall
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 1.2 | Low |
| Typical, some insulation, not air-sealed | 2.0 | Low |
| Older or poorly insulated, warm attic | 3.0 | Low |
The attic matters less in Marshall than in colder towns: there are only 0.8 days a winter between a typical attic and a sealed one.
What to do about ice dams in Marshall
- 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.
Marshall winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 3.0 | 2.7 | 0.9 |
| February | 2.2 | 2.8 | 0.7 |
| March | 0.9 | 0.6 | 0.1 |
| October | 0.1 | 0.0 | 0.0 |
| November | 0.3 | 0.4 | 0.1 |
| December | 1.6 | 1.0 | 0.3 |
Marshall next to nearby towns
Marshall ranks 70 of 80 Missouri cities here for ice-dam days, behind Maryville at 9.3 days.
- Sedalia, MO 28 mi, 3.0 days
- Warrensburg, MO 37 mi, 4.8 days
- Moberly, MO 46 mi, 2.9 days
- Columbia, MO 48 mi, 4.6 days
- Grain Valley, MO 55 mi, 5.2 days
Where these numbers come from
NOAA 1991–2020 climate normals from Marshall, 1.7 miles from Marshall. 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.