Black Hawk County, IA Roof Snow Load - 21 psf
Black Hawk County, IA: your roof's ASCE 7 snow number, in plain English
Black Hawk County's roofs are built to hold 21 psf of snow, the ASCE 7-22 figure a permit reviewer checks first.
In depth, not weight: that's roughly 46.2 inches of fresh, light snow, 16.8 inches of old, settled snow, or as little as 4.2 inches of solid ice - snow that heavy is rare here but ice from a freeze-thaw cycle adds up far faster than the depth suggests. A meaningful design load. Most homes built to modern code handle it, but additions, carports, and flat-roofed sections are worth a second look.
Black Hawk County, IA: quick facts
- Design roof snow load21 psf
- Ground snow load, ASCE 7 map30 psf
- National rank#413 of 2,758
- Iowa rank#27 of 99
- Population132,348
- Annual snowfall, NOAA normal33.9 in.
- FIPS19013
Black Hawk County by the numbers
Nationally that's #413 out of 2,758 rated counties, the top 15%; within Iowa alone, Black Hawk County ranks #27 of 99. Iowa counties average 21.7 psf; Black Hawk County runs 0.7 psf lower than that.
Black Hawk County, FIPS 19013, is home to 132,348 people near 42.4711°N 92.3076°W. Its 30 psf ground snow load figure is the map value; 21 psf is what a roof is actually designed for.
Black Hawk County's snowfall, most winters
33.9 in. a year: that's Black Hawk County's NOAA 1991-2020 snowfall normal, measured at INDEPENDENCE #1, IA US (22.2 mi away). See the density guide.
Before you rely on Black Hawk County's number
Treat the Black Hawk County figure as a starting point, not a final answer: it assumes standard occupancy, a heated structure and a moderately sheltered site, per ASCE 7-22's own defaults. Exposed terrain, an unheated building or a steeper roof all shift the real number.
For a real application, skip the county number and go straight to the ASCE 7 Hazard Tool - enter your coordinates and it returns a site-specific figure a plan reviewer will recognize. Details: the calculation guide.