SnowLoadCheck

Jackson County, IL Roof Snow Load - 15 psf

How much snow is too much for a roof in Jackson County, IL?

Moderate
15 psf

15 psf: that's what ASCE 7-22 requires a typical heated home's roof in Jackson County to carry. ASCE 7's low-slope-roof minimum (§7.3.4) raises the governing figure to 15 psf - higher than the 10.5 psf the ground-load formula alone would give, and the code says use the larger one.

Picture it, not just weigh it: 33 in. if it's fresh powder, 12 in. once it settles, or a mere 3 in. if it's 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.

Snow on Jackson County's roofs right now?

in. of

Jackson County at a glance

How Jackson County compares

15 psf ranks #1,377 of 2,758 US counties with a mapped snow load (top 50%) - and #90 of 102 in Illinois. 19.3 psf is Illinois's typical county figure - Jackson County comes in 4.3 psf under it.

Population 53,199 (FIPS 17077), roughly 37.7861°N 89.3812°W. The 15 psf ground snow load ASCE 7-22 maps here becomes 15 psf once the code's own design factors are applied.

Typical snowfall in Jackson County, IL

NOAA's 30-year normal for Jackson County: 9.9 in. of snow a year, from the MURPHYSBORO 2 SW, IL US station. (fresh vs. packed vs. ice explains why.)

What this Jackson County figure assumes

This is a county-level reference figure for a typical heated home built to Risk Category II (ordinary residential), on a partially exposed lot - the assumptions ASCE 7-22 itself treats as the default case. A steeper roof, a fully exposed hilltop lot, an unheated structure, or a higher risk category all change the actual number.

Jackson County's permit office wants an address-specific figure, not this county average - the ASCE 7 Hazard Tool is free, takes under a minute, and outputs a PDF most reviewers accept. Details: the calculation guide.