Pottawattamie County, IA Roof Snow Load - 20 psf
What ASCE 7 says about snow load in Pottawattamie County
That's Pottawattamie County's design roof snow load per ASCE 7-22, for a typical heated single-family home - the number a permit reviewer starts from. Flat and low-pitch roofs in Pottawattamie County are actually governed by ASCE 7's §7.3.4 minimum of 20 psf, not the 17.5 psf the ground-load formula alone would produce.
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.
Pottawattamie County at a glance
- Design roof snow load20 psf
- Ground snow load, ASCE 7 map25 psf
- National rank#661 of 2,758
- Iowa rank#49 of 99
- Population93,529
- Annual snowfall, NOAA normal27.3 in.
- FIPS19155
Where Pottawattamie County's figure sits nationally
Out of 2,758 rated US counties, Pottawattamie County sits at #661, the top 24% nationally - #49 of 99 within Iowa. That's 1.7 psf below Iowa's own county-average design load of 21.7 psf.
Near 41.3402°N 95.5449°W, FIPS 19155: Pottawattamie County counts 93,529 residents and a 25 psf map value, which the code's own factors turn into 20 psf.
How much it actually snows in Pottawattamie County
Most winters bring Pottawattamie County roughly 27.3 in. of snow - NOAA's normal at UNDERWOOD, IA US, 7.8 mi off. (fresh vs. packed vs. ice explains why.)
Read this before you rely on it
Pottawattamie 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 Pottawattamie County's county-wide figure. Details: the calculation guide.