SnowLoadCheck

Lucas County, IA Roof Snow Load - 20 psf

What ASCE 7 says about snow load in Lucas County

Moderate
20 psf

That's Lucas County's design roof snow load per ASCE 7-22, for a typical heated single-family home - the number a permit reviewer starts from. The physics-based figure alone would be 14 psf, but ASCE 7's own low-slope minimum (§7.3.4) sets a floor of 20 psf for flat and low-pitch roofs here, which is the number that actually governs.

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. This is a meaningful design load - most modern-code homes handle it fine, though an addition, a carport or a flat-roofed section can be a weak spot.

Lucas County at a glance

Where Lucas County's figure sits nationally

Out of 2,758 rated US counties, Lucas County sits at #1,131, the top 41% nationally - #87 of 99 within Iowa. 21.7 psf is Iowa's typical county figure - Lucas County comes in 1.7 psf under it.

Near 41.0333°N 93.3315°W, FIPS 19117: Lucas County counts 8,758 residents and a 20 psf map value, which the code's own factors turn into 20 psf.

How much it actually snows in Lucas County

Most winters bring Lucas County roughly 24.1 in. of snow - NOAA's normal at CHARITON 1 E, IA US, 3 mi off. (fresh vs. packed vs. ice explains why.)

Read this before you rely on it

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