Adams County, IA Roof Snow Load - 20 psf
What ASCE 7 says about snow load in Adams County
That's Adams County's design roof snow load per ASCE 7-22, for a typical heated single-family home - the number a permit reviewer starts from. 14 psf is what the ground-load formula alone gives; Adams 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.
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. A meaningful design load. Most homes built to modern code handle it, but additions, carports, and flat-roofed sections are worth a second look.
Adams County, IA: quick facts
- Design roof snow load20 psf
- Ground snow load, ASCE 7 map20 psf
- National rank#1,241 of 2,758
- Iowa rank#99 of 99
- Population3,606
- Annual snowfall, NOAA normal25.5 in.
- FIPS19003
Where Adams County's figure sits nationally
Out of 2,758 rated US counties, Adams County sits at #1,241, the top 45% nationally - #99 of 99 within Iowa. 21.7 psf is Iowa's typical county figure - Adams County comes in 1.7 psf under it.
Near 41.0217°N 94.6969°W, FIPS 19003: Adams County counts 3,606 residents and a 20 psf map value, which the code's own factors turn into 20 psf.
How much it actually snows in Adams County
Most winters bring Adams County roughly 25.5 in. of snow - NOAA's normal at GREENFIELD, IA US, 22.9 mi off. (fresh vs. packed vs. ice explains why.)
Read this before you rely on it
Adams 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 Adams County's county-wide figure. See the methodology guide.