SnowLoadCheck

Greene County, IA Roof Snow Load - 20 psf

What ASCE 7 says about snow load in Greene County

Moderate
20 psf

That's Greene 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.

Greene County, IA: quick facts

Where Greene County's figure sits nationally

Out of 2,758 rated US counties, Greene County sits at #1,134, the top 41% nationally - #88 of 99 within Iowa. 21.7 psf is Iowa's typical county figure - Greene County comes in 1.7 psf under it.

Near 42.0425°N 94.3887°W, FIPS 19073: Greene County counts 8,662 residents and a 25 psf map value, which the code's own factors turn into 20 psf.

How much it actually snows in Greene County

Most winters bring Greene County roughly 31.7 in. of snow - NOAA's normal at JEFFERSON, IA US, 2.3 mi off. (fresh vs. packed vs. ice explains why.)

Read this before you rely on it

Greene 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 Greene County's county-wide figure. See the methodology guide.