SnowLoadCheck

Harford County, MD Roof Snow Load - 20 psf

Harford County, MD: your roof's ASCE 7 snow number, in plain English

Moderate
20 psf

Harford 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.

Harford County at a glance

Harford County by the numbers

Nationally that's #569 out of 2,758 rated counties, the top 21%; within Maryland alone, Harford County ranks #9 of 21. That's 0.1 psf below Maryland's own county-average design load of 20.1 psf.

Harford County, FIPS 24025, is home to 265,514 people near 39.5374°N 76.2998°W. Its 25 psf ground snow load figure is the map value; 20 psf is what a roof is actually designed for.

Harford County's snowfall, most winters

28.8 in. a year: that's Harford County's NOAA 1991-2020 snowfall normal, measured at NEW PARK, PA US (17.4 mi away). See the density guide.

Before you rely on Harford County's number

Treat the Harford 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. See the methodology guide.