Canyon County, ID Roof Snow Load - 10 psf
Canyon County, ID: your roof's ASCE 7 snow number, in plain English
Canyon County's roofs are built to hold 10 psf of snow, the ASCE 7-22 figure a permit reviewer checks first. 7 psf is what the ground-load formula alone gives; Canyon County's 10 psf low-slope minimum (§7.3.4) beats it, so that figure is the one that governs on flat and low-pitch roofs.
In depth, not weight: that's roughly 22 inches of fresh, light snow, 8 inches of old, settled snow, or as little as 2 inches of solid ice - snow that heavy is rare here but ice from a freeze-thaw cycle adds up far faster than the depth suggests. A modest addition to standard roof loading. Ordinary residential construction handles this without extra bracing.
Canyon County at a glance
- Design roof snow load10 psf
- Ground snow load, ASCE 7 map10 psf
- National rank#1,671 of 2,758
- Idaho rank#4 of 9
- Population266,892
- Annual snowfall, NOAA normal9.7 in.
- FIPS16027
Canyon County by the numbers
Nationally that's #1,671 out of 2,758 rated counties, the top 61%; within Idaho alone, Canyon County ranks #4 of 9. That's 2.2 psf below Idaho's own county-average design load of 12.2 psf.
Canyon County, FIPS 16027, is home to 266,892 people near 43.6258°N 116.7091°W. Its 10 psf ground snow load figure is the map value; 10 psf is what a roof is actually designed for.
Canyon County's snowfall, most winters
9.7 in. a year: that's Canyon County's NOAA 1991-2020 snowfall normal, measured at NAMPA SUGAR FACTORY, ID US (6.9 mi away). See the density guide.
Before you rely on Canyon County's number
Treat the Canyon 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.)