Lawrence County, IL Roof Snow Load - 20 psf
What ASCE 7 says about snow load in Lawrence County
That's Lawrence County's design roof snow load per ASCE 7-22, for a typical heated single-family home - the number a permit reviewer starts from. §7.3.4's low-slope minimum of 20 psf is what actually governs on a flat or low-pitch roof here - higher than the 14 psf the base ground-load formula gives.
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.
Snow on Lawrence County's roofs right now?
Lawrence County in numbers
- Design roof snow load20 psf
- Ground snow load, ASCE 7 map20 psf
- National rank#1,030 of 2,758
- Illinois rank#67 of 102
- Population14,801
- Annual snowfall, NOAA normal15.5 in.
- FIPS17101
Where Lawrence County's figure sits nationally
Out of 2,758 rated US counties, Lawrence County sits at #1,030, the top 37% nationally - #67 of 102 within Illinois. 19.3 psf is Illinois's typical county figure - Lawrence County beats it by 0.7 psf.
Near 38.719°N 87.7302°W, FIPS 17101: Lawrence County counts 14,801 residents and a 20 psf map value, which the code's own factors turn into 20 psf.
How much it actually snows in Lawrence County
Most winters bring Lawrence County roughly 15.5 in. of snow - NOAA's normal at LAWRENCEVILLE 2WSW, IL US, 0.7 mi off. (fresh vs. packed vs. ice explains why.)
Read this before you rely on it
Lawrence 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 Lawrence County's county-wide figure. See the methodology guide.