Benton County, IA Roof Snow Load - 20 psf
What ASCE 7 says about snow load in Benton County
That's Benton County's design roof snow load per ASCE 7-22, for a typical heated single-family home - the number a permit reviewer starts from. ASCE 7's low-slope-roof minimum (§7.3.4) raises the governing figure to 20 psf - higher than the 17.5 psf the ground-load formula alone would give, and the code says use the larger one.
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. 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.
Benton County in numbers
- Design roof snow load20 psf
- Ground snow load, ASCE 7 map25 psf
- National rank#903 of 2,758
- Iowa rank#60 of 99
- Population25,799
- Annual snowfall, NOAA normal33.6 in.
- FIPS19011
Where Benton County's figure sits nationally
Out of 2,758 rated US counties, Benton County sits at #903, the top 33% nationally - #60 of 99 within Iowa. 21.7 psf is Iowa's typical county figure - Benton County comes in 1.7 psf under it.
Near 42.0925°N 92.0576°W, FIPS 19011: Benton County counts 25,799 residents and a 25 psf map value, which the code's own factors turn into 20 psf.
How much it actually snows in Benton County
Most winters bring Benton County roughly 33.6 in. of snow - NOAA's normal at VINTON, IA US, 5.9 mi off. (fresh vs. packed vs. ice explains why.)
Read this before you rely on it
Benton 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 Benton County's county-wide figure. (How this figure is calculated.)