Calhoun County, IA Roof Snow Load - 21 psf

How much snow is too much for a roof in Calhoun County, IA?

Picture it, not just weigh it: 46.2 in. if it's fresh powder, 16.8 in. once it settles, or a mere 4.2 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 in numbers

• Design roof snow load21 psf
• Ground snow load, ASCE 7 map30 psf
• National rank#471 of 2,758
• Iowa rank#40 of 99
• Population9,711
• Annual snowfall, NOAA normal32.1 in.
• FIPS19025

How Calhoun County compares

21 psf ranks #471 of 2,758 US counties with a mapped snow load (top 17%) - and #40 of 99 in Iowa. 21.7 psf is Iowa's typical county figure - Calhoun County comes in 0.7 psf under it.

Population 9,711 (FIPS 19025), roughly 42.3861°N 94.6436°W. The 30 psf ground snow load ASCE 7-22 maps here becomes 21 psf once the code's own design factors are applied.

Typical snowfall in Calhoun County, IA

NOAA's 30-year normal for Calhoun County: 32.1 in. of snow a year, from the ROCKWELL CITY, IA 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. Details: the calculation guide.