Jefferson County, ID Roof Snow Load - Case Study Area
What "Case Study" means for Jefferson County
ASCE 7's own snow load map has no single figure for Jefferson County: the terrain is complex enough that the code (§7.2) requires an elevation-specific study rather than a county-wide value. That is the map being accurate, not a data gap.
FIPS 16051, population 34,854. 386 US counties get this same case-study treatment; Jefferson County is one of them.
Jefferson County in numbers
- Population34,854
- Annual snowfall, NOAA normal20.4 in.
- FIPS16051
Jefferson County's snowfall, most winters
20.4 in. a year: that's Jefferson County's NOAA 1991-2020 snowfall normal, measured at HAMER 4 NW, ID US (12 mi away). See the density guide.
Before you rely on Jefferson County's number
Treat the Jefferson County figure as a starting point, not a final answer: it assumes standard occupancy, a heated structure and a moderately sheltered site, per ASCE 7-22's own defaults. Exposed terrain, an unheated building or a steeper roof all shift the real number.
For a real application, skip the county number and go straight to the ASCE 7 Hazard Tool - enter your coordinates and it returns a site-specific figure a plan reviewer will recognize. Details: the calculation guide.