Douglas County, MO Roof Snow Load - 15 psf
Douglas County, MO: your roof's ASCE 7 snow number, in plain English
Douglas 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; Douglas 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. Modern-code homes carry a load like this without issue; an older addition, a carport, or any flat-roofed section is where it is worth checking first.
Douglas County at a glance
- Design roof snow load15 psf
- Ground snow load, ASCE 7 map15 psf
- National rank#1,533 of 2,758
- Missouri rank#102 of 115
- Population12,290
- Annual snowfall, NOAA normal7.7 in.
- FIPS29067
Douglas County by the numbers
Nationally that's #1,533 out of 2,758 rated counties, the top 56%; within Missouri alone, Douglas County ranks #102 of 115. Missouri counties average 18.6 psf; Douglas County runs 3.6 psf lower than that.
Douglas County, FIPS 29067, is home to 12,290 people near 36.9465°N 92.5159°W. Its 15 psf ground snow load figure is the map value; 15 psf is what a roof is actually designed for.
Douglas County's snowfall, most winters
7.7 in. a year: that's Douglas County's NOAA 1991-2020 snowfall normal, measured at MANSFIELD, MO US (11.7 mi away). See the density guide.
Before you rely on Douglas County's number
Treat the Douglas 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.