SnowLoadCheck

Harrison County, MO Roof Snow Load - 20 psf

How much snow is too much for a roof in Harrison County, MO?

Moderate
20 psf

20 psf: that's what ASCE 7-22 requires a typical heated home's roof in Harrison County to carry. 14 psf is what the ground-load formula alone gives; Harrison County's 20 psf low-slope minimum (§7.3.4) beats it, so that figure is the one that governs on flat and low-pitch roofs.

Picture it, not just weigh it: 44 in. if it's fresh powder, 16 in. once it settles, or a mere 4 in. if it's ice. 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.

Already snow on the roof in Harrison County?

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Harrison County at a glance

How Harrison County compares

20 psf ranks #1,146 of 2,758 US counties with a mapped snow load (top 42%) - and #71 of 115 in Missouri. 18.6 psf is Missouri's typical county figure - Harrison County beats it by 1.4 psf.

Population 8,186 (FIPS 29081), roughly 40.3456°N 93.9926°W. The 20 psf ground snow load ASCE 7-22 maps here becomes 20 psf once the code's own design factors are applied.

Typical snowfall in Harrison County, MO

NOAA's 30-year normal for Harrison County: 21.2 in. of snow a year, from the BETHANY, MO US station. (fresh vs. packed vs. ice explains why.)

What this Harrison 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.

Harrison 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. See the methodology guide.