Plymouth County, IA Roof Snow Load - 24.5 psf
What ASCE 7 says about snow load in Plymouth County
That's Plymouth County's design roof snow load per ASCE 7-22, for a typical heated single-family home - the number a permit reviewer starts from.
Converted to something you can actually eyeball on a roof: about 53.9 in. of fresh powder, 19.6 in. once it settles and packs down, or just 4.9 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.
Plymouth County, IA: quick facts
- Design roof snow load24.5 psf
- Ground snow load, ASCE 7 map35 psf
- National rank#334 of 2,758
- Iowa rank#12 of 99
- Population25,825
- Annual snowfall, NOAA normal36.6 in.
- FIPS19149
Where Plymouth County's figure sits nationally
Out of 2,758 rated US counties, Plymouth County sits at #334, the top 12% nationally - #12 of 99 within Iowa. That's 2.8 psf above Iowa's own county-average design load of 21.7 psf.
Near 42.7376°N 96.216°W, FIPS 19149: Plymouth County counts 25,825 residents and a 35 psf map value, which the code's own factors turn into 24.5 psf.
How much it actually snows in Plymouth County
Most winters bring Plymouth County roughly 36.6 in. of snow - NOAA's normal at AKRON, IA US, 18.1 mi off. (fresh vs. packed vs. ice explains why.)
Read this before you rely on it
Plymouth 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 Plymouth County's county-wide figure. Details: the calculation guide.