Ice dam risk in Ottawa, KS
Will your roof get ice dams in Ottawa, KS?
2.9 dam days a winter
Low risk. On an ordinary house in Ottawa, conditions for an ice dam come on about 2.9 days in a normal winter, mostly in January and December.
Ottawa averages 9 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 Ottawa
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 2.0 | Low |
| Typical, some insulation, not air-sealed | 2.9 | Low |
| Older or poorly insulated, warm attic | 4.1 | Low |
The attic matters less in Ottawa than in colder towns: there are only 0.9 days a winter between a typical attic and a sealed one.
What to do about ice dams in Ottawa
- 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.
Ottawa winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 3.2 | 5.3 | 1.5 |
| February | 2.1 | 2.5 | 0.6 |
| March | 0.7 | 0.8 | 0.1 |
| October | 0.1 | 0.1 | 0.0 |
| November | 0.5 | 0.3 | 0.0 |
| December | 2.6 | 2.6 | 0.6 |
Ottawa next to nearby towns
Ottawa ranks 26 of 38 Kansas cities here for ice-dam days, behind Salina at 5.8 days.
- Gardner, KS 24 mi, 4.4 days
- Lawrence, KS 25 mi, 3.1 days
- Spring Hill, KS 26 mi, 4.4 days
- Olathe, KS 31 mi, 4.4 days
- Lenexa, KS 35 mi, 4.4 days
Where these numbers come from
NOAA 1991–2020 climate normals from Ottawa, 1.4 miles from Ottawa. 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.
- Snow-on-the-ground counts come from a second, nearby station, because the closest one does not record them.