Ice dam risk in South Lake Tahoe, CA
Ice dams in South Lake Tahoe, CA: how often
2.1 dam days a winter
Low risk. On an ordinary house in South Lake Tahoe, conditions for an ice dam come on about 2.1 days in a normal winter, mostly in January and December.
South Lake Tahoe averages 22 inches of snow a year and about 9 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 South Lake Tahoe
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 1.9 | Low |
| Typical, some insulation, not air-sealed | 2.1 | Low |
| Older or poorly insulated, warm attic | 2.3 | Low |
The attic matters less in South Lake Tahoe than in colder towns: there are only 0.2 days a winter between a typical attic and a sealed one.
What to do about ice dams in South Lake Tahoe
- 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.
South Lake Tahoe winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 5.6 | 2.9 | 0.7 |
| February | 4.1 | 2.0 | 0.5 |
| March | 3.4 | 0.6 | 0.1 |
| April | 1.5 | 0.0 | 0.0 |
| May | 0.1 | 0.0 | 0.0 |
| June | 0.1 | 0.0 | 0.0 |
| October | 0.2 | 0.0 | 0.0 |
| November | 1.6 | 0.6 | 0.1 |
| December | 5.2 | 2.5 | 0.6 |
South Lake Tahoe next to nearby towns
South Lake Tahoe ranks 4 of 376 California cities here for ice-dam days, behind Truckee at 36.3 days.
- Carson, NV 20 mi, 1.9 days
- Truckee, CA 31 mi, 36.3 days
- Reno, NV 43 mi, 3.1 days
- Placerville, CA 46 mi, 7.6 days
- Sparks, NV 47 mi, 1.3 days
Where these numbers come from
NOAA 1991–2020 climate normals from Minden, 11.2 miles from South Lake Tahoe. 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.