Shannon County, MO Roof Snow Load - 15 psf
Shannon County, MO: your roof's ASCE 7 snow number, in plain English
Shannon County's roofs are built to hold 15 psf of snow, the ASCE 7-22 figure a permit reviewer checks first. 10.5 psf is what the ground-load formula alone gives; Shannon County's 15 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 33 inches of fresh, light snow, 12 inches of old, settled snow, or as little as 3 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 meaningful design load. Most homes built to modern code handle it, but additions, carports, and flat-roofed sections are worth a second look.
Shannon County in numbers
- Design roof snow load15 psf
- Ground snow load, ASCE 7 map15 psf
- National rank#1,584 of 2,758
- Missouri rank#111 of 115
- Population7,275
- Annual snowfall, NOAA normal6 in.
- FIPS29203
Shannon County by the numbers
Nationally that's #1,584 out of 2,758 rated counties, the top 57%; within Missouri alone, Shannon County ranks #111 of 115. 18.6 psf is Missouri's typical county figure - Shannon County comes in 3.6 psf under it.
Shannon County, FIPS 29203, is home to 7,275 people near 37.1525°N 91.3913°W. Its 15 psf ground snow load figure is the map value; 15 psf is what a roof is actually designed for.
Shannon County's snowfall, most winters
6 in. a year: that's Shannon County's NOAA 1991-2020 snowfall normal, measured at EMINENCE 1 N, MO US (1.7 mi away). See the density guide.
Before you rely on Shannon County's number
Treat the Shannon 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.)