SnowLoadCheck

Montgomery County, IA Roof Snow Load - 20 psf

Montgomery County, IA: your roof's ASCE 7 snow number, in plain English

Moderate
20 psf

Montgomery County's roofs are built to hold 20 psf of snow, the ASCE 7-22 figure a permit reviewer checks first. §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 17.5 psf the base ground-load formula gives.

In depth, not weight: that's roughly 44 inches of fresh, light snow, 16 inches of old, settled snow, or as little as 4 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.

Montgomery County in numbers

Montgomery County by the numbers

Nationally that's #1,099 out of 2,758 rated counties, the top 40%; within Iowa alone, Montgomery County ranks #83 of 99. 21.7 psf is Iowa's typical county figure - Montgomery County comes in 1.7 psf under it.

Montgomery County, FIPS 19137, is home to 10,063 people near 41.0217°N 95.1578°W. Its 25 psf ground snow load figure is the map value; 20 psf is what a roof is actually designed for.

Montgomery County's snowfall, most winters

27.4 in. a year: that's Montgomery County's NOAA 1991-2020 snowfall normal, measured at RED OAK, IA US (4.6 mi away). See the density guide.

Before you rely on Montgomery County's number

Treat the Montgomery 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. (How this figure is calculated.)