Ice dam risk in Lexington, NE
Will your roof get ice dams in Lexington, NE?
13.8 dam days a winter
Moderate risk. On an ordinary house in Lexington, conditions for an ice dam come on about 13.8 days in a normal winter, mostly in January and February.
Lexington averages 20 inches of snow a year and about 48 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 Lexington
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 8.8 | Moderate |
| Typical, some insulation, not air-sealed | 13.8 | Moderate |
| Older or poorly insulated, warm attic | 19.9 | High |
Sealing and insulating a typical attic takes out about 4.9 days a winter here. It does not move the risk band, but it shortens every dam. An older house with a warm attic should expect closer to 19.9 days.
Preventing ice dams on a Lexington roof
- 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.
Which to spend on first: air sealing or heat cable.
Lexington winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 5.9 | 13.7 | 4.6 |
| February | 4.9 | 12.3 | 3.8 |
| March | 2.3 | 4.7 | 1.0 |
| April | 1.0 | 1.5 | 0.1 |
| May | 0.1 | 0.1 | 0.0 |
| October | 0.6 | 0.9 | 0.1 |
| November | 1.9 | 3.4 | 0.8 |
| December | 3.3 | 10.9 | 3.4 |
Lexington next to nearby towns
Lexington ranks 5 of 16 Nebraska cities here for ice-dam days, behind South Sioux City at 19.2 days.
- Kearney, NE 35 mi, 10.1 days
- North Platte, NE 58 mi, 9.4 days
- Hastings, NE 72 mi, 11.3 days
- Grand Island, NE 73 mi, 11.6 days
- Columbus, NE 132 mi, 12.5 days
Where these numbers come from
NOAA 1991–2020 climate normals from Canaday Steam Plt, 6.2 miles from Lexington. 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.