Knox County, MO Roof Snow Load - 20 psf
How much snow is too much for a roof in Knox County, MO?
20 psf: that's what ASCE 7-22 requires a typical heated home's roof in Knox County to carry. ASCE 7's low-slope-roof minimum (§7.3.4) raises the governing figure to 20 psf - higher than the 14 psf the ground-load formula alone would give, and the code says use the larger one.
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. This is a meaningful design load - most modern-code homes handle it fine, though an addition, a carport or a flat-roofed section can be a weak spot.
Knox County in numbers
- Design roof snow load20 psf
- Ground snow load, ASCE 7 map20 psf
- National rank#1,240 of 2,758
- Missouri rank#82 of 115
- Population3,740
- Annual snowfall, NOAA normal19.8 in.
- FIPS29103
How Knox County compares
20 psf ranks #1,240 of 2,758 US counties with a mapped snow load (top 45%) - and #82 of 115 in Missouri. That's 1.4 psf above Missouri's own county-average design load of 18.6 psf.
Population 3,740 (FIPS 29103), roughly 40.1369°N 92.1468°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 Knox County, MO
NOAA's 30-year normal for Knox County: 19.8 in. of snow a year, from the EDINA, MO US station. (fresh vs. packed vs. ice explains why.)
What this Knox 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.
Knox 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.