Sullivan County, MO Roof Snow Load - 20 psf
What ASCE 7 says about snow load in Sullivan County
That's Sullivan County's design roof snow load per ASCE 7-22, for a typical heated single-family home - the number a permit reviewer starts from. §7.3.4's low-slope minimum of 20 psf is what actually governs on a flat or low-pitch roof here - higher than the 14 psf the base ground-load formula gives.
Converted to something you can actually eyeball on a roof: about 44 in. of fresh powder, 16 in. once it settles and packs down, or just 4 in. if it's turned to 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.
Already snow on the roof in Sullivan County?
Sullivan County at a glance
- Design roof snow load20 psf
- Ground snow load, ASCE 7 map20 psf
- National rank#1,204 of 2,758
- Missouri rank#76 of 115
- Population5,750
- Annual snowfall, NOAA normal17 in.
- FIPS29211
Where Sullivan County's figure sits nationally
Out of 2,758 rated US counties, Sullivan County sits at #1,204, the top 44% nationally - #76 of 115 within Missouri. 18.6 psf is Missouri's typical county figure - Sullivan County beats it by 1.4 psf.
Near 40.2096°N 93.1098°W, FIPS 29211: Sullivan County counts 5,750 residents and a 20 psf map value, which the code's own factors turn into 20 psf.
How much it actually snows in Sullivan County
Most winters bring Sullivan County roughly 17 in. of snow - NOAA's normal at MILAN, MO US, 0.8 mi off. (fresh vs. packed vs. ice explains why.)
Read this before you rely on it
Sullivan County's number above is ASCE 7-22's default case, not a custom calculation: ordinary residential occupancy, heated, sited on ground that's neither fully sheltered nor fully exposed. Any one of those changing - pitch, exposure, heating, occupancy - moves the real figure.
Nothing here substitutes for an address-level number. Get one free, in about a minute, from the ASCE 7 Hazard Tool using your own coordinates rather than Sullivan County's county-wide figure. Details: the calculation guide.