Lyon County, KS Roof Snow Load - 20 psf
What ASCE 7 says about snow load in Lyon County
That's Lyon 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. 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.
Lyon County, KS: quick facts
- Design roof snow load20 psf
- Ground snow load, ASCE 7 map20 psf
- National rank#847 of 2,758
- Kansas rank#11 of 105
- Population32,520
- Annual snowfall, NOAA normal10.1 in.
- FIPS20111
Where Lyon County's figure sits nationally
Out of 2,758 rated US counties, Lyon County sits at #847, the top 31% nationally - #11 of 105 within Kansas. 18.2 psf is Kansas's typical county figure - Lyon County beats it by 1.8 psf.
Near 38.4554°N 96.1616°W, FIPS 20111: Lyon County counts 32,520 residents and a 20 psf map value, which the code's own factors turn into 20 psf.
How much it actually snows in Lyon County
Most winters bring Lyon County roughly 10.1 in. of snow - NOAA's normal at DUNLAP 2 N, KS US, 15.3 mi off. (fresh vs. packed vs. ice explains why.)
Read this before you rely on it
Lyon 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 Lyon County's county-wide figure. (How this figure is calculated.)