SnowLoadCheck

Wapello County, IA Roof Snow Load - 20 psf

What ASCE 7 says about snow load in Wapello County

Moderate
20 psf

That's Wapello 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 14 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. A meaningful design load. Most homes built to modern code handle it, but additions, carports, and flat-roofed sections are worth a second look.

Wapello County in numbers

Where Wapello County's figure sits nationally

Out of 2,758 rated US counties, Wapello County sits at #813, the top 29% nationally - #56 of 99 within Iowa. Iowa counties average 21.7 psf; Wapello County runs 1.7 psf lower than that.

Near 41.0313°N 92.4095°W, FIPS 19179: Wapello County counts 35,681 residents and a 20 psf map value, which the code's own factors turn into 20 psf.

How much it actually snows in Wapello County

Most winters bring Wapello County roughly 23.6 in. of snow - NOAA's normal at OTTUMWA INDUSTRIAL AP, IA US, 5.6 mi off. (fresh vs. packed vs. ice explains why.)

Read this before you rely on it

Wapello 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 Wapello County's county-wide figure. Details: the calculation guide.