SnowLoadCheck

Custer County, ID Roof Snow Load - Case Study Area

What "Case Study" means for Custer County

Case study area
No map value

ASCE 7's own snow load map has no single figure for Custer 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 16037, population 4,597. 386 US counties get this same case-study treatment; Custer County is one of them.

Custer County at a glance

Custer County's snowfall, most winters

18.3 in. a year: that's Custer County's NOAA 1991-2020 snowfall normal, measured at CHILLY BARTON FLAT, ID US (29.3 mi away). 29.3 mi is a real gap between Custer County and its nearest reporting station, so local snowfall can diverge from this figure, especially near elevation changes. See the density guide.

Before you rely on Custer County's number

Treat the Custer 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. (How this figure is calculated.)