Calhoun County, MI Roof Snow Load - 20 psf
How much snow is too much for a roof in Calhoun County, MI?
20 psf: that's what ASCE 7-22 requires a typical heated home's roof in Calhoun County to carry. Flat and low-pitch roofs in Calhoun 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.
Picture it, not just weigh it: 44 in. if it's fresh powder, 16 in. once it settles, or a mere 4 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.
Calhoun County, MI: quick facts
- Design roof snow load20 psf
- Ground snow load, ASCE 7 map25 psf
- National rank#626 of 2,758
- Michigan rank#65 of 70
- Population133,785
- Annual snowfall, NOAA normal40.4 in.
- FIPS26025
How Calhoun County compares
20 psf ranks #626 of 2,758 US counties with a mapped snow load (top 23%) - and #65 of 70 in Michigan. Michigan counties average 31.7 psf; Calhoun County runs 11.7 psf lower than that.
Population 133,785 (FIPS 26025), roughly 42.243°N 85.0124°W. The 25 psf ground snow load ASCE 7-22 maps here becomes 20 psf once the code's own design factors are applied.
Typical snowfall in Calhoun County, MI
NOAA's 30-year normal for Calhoun County: 40.4 in. of snow a year, from the ALBION, MI US station. (fresh vs. packed vs. ice explains why.)
What this Calhoun 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.
Calhoun 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. See the methodology guide.