Walworth County, WI Roof Snow Load - 20 psf
What ASCE 7 says about snow load in Walworth County
That's Walworth 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 Walworth 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. 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.
Walworth County in numbers
- Design roof snow load20 psf
- Ground snow load, ASCE 7 map25 psf
- National rank#648 of 2,758
- Wisconsin rank#72 of 72
- Population106,029
- Annual snowfall, NOAA normal40.1 in.
- FIPS55127
Where Walworth County's figure sits nationally
Out of 2,758 rated US counties, Walworth County sits at #648, the top 23% nationally - #72 of 72 within Wisconsin. That's 10.9 psf below Wisconsin's own county-average design load of 30.9 psf.
Near 42.6681°N 88.5417°W, FIPS 55127: Walworth County counts 106,029 residents and a 25 psf map value, which the code's own factors turn into 20 psf.
How much it actually snows in Walworth County
Most winters bring Walworth County roughly 40.1 in. of snow - NOAA's normal at LAKE GENEVA WWTP, WI US, 7.5 mi off. (fresh vs. packed vs. ice explains why.)
Read this before you rely on it
Walworth 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 Walworth County's county-wide figure. (How this figure is calculated.)