Caribou County, ID Roof Snow Load - Case Study Area

What "Case Study" means for Caribou County

Case study area

No map value

Caribou County sits in the mountain-west terrain where ASCE 7-22 §7.2 itself declines to give a contour figure - elevation changes too fast over short distances there for one number per county to mean anything. The code requires a site-specific study for a building here, not a look-up.

Caribou County, FIPS 16029, is home to 7,239 people - one of 386 US counties ASCE 7 itself routes around a map figure for.

Caribou County in numbers

Population7,239
Annual snowfall, NOAA normal87.8 in.
FIPS16029

Typical snowfall in Caribou County, ID

NOAA's 30-year normal for Caribou County: 87.8 in. of snow a year, from the AFTON, WY US station. That station is far enough away (31.8 mi) that local snowfall - especially at a different elevation or near a lake - can run noticeably higher or lower than this figure. (fresh vs. packed vs. ice explains why.)

What this Caribou County figure assumes

This is a county-level reference figure for a typical heated home built to Risk Category II (ordinary residential), on a partially exposed lot - the assumptions ASCE 7-22 itself treats as the default case. A steeper roof, a fully exposed hilltop lot, an unheated structure, or a higher risk category all change the actual number.

Caribou County's permit office wants an address-specific figure, not this county average - the ASCE 7 Hazard Tool is free, takes under a minute, and outputs a PDF most reviewers accept. (How this figure is calculated.)