Baltimore city, MD Roof Snow Load - 20 psf
Baltimore city, MD: your roof's ASCE 7 snow number, in plain English
Baltimore city's roofs are built to hold 20 psf of snow, the ASCE 7-22 figure a permit reviewer checks first. ASCE 7's low-slope-roof minimum (§7.3.4) raises the governing figure to 20 psf - higher than the 17.5 psf the ground-load formula alone would give, and the code says use the larger one.
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.
Baltimore city in numbers
- Design roof snow load20 psf
- Ground snow load, ASCE 7 map25 psf
- National rank#535 of 2,758
- Maryland rank#7 of 21
- Population568,271
- Annual snowfall, NOAA normal28.5 in.
- FIPS24510
Baltimore city by the numbers
Nationally that's #535 out of 2,758 rated counties, the top 19%; within Maryland alone, Baltimore city ranks #7 of 21. That's 0.1 psf below Maryland's own county-average design load of 20.1 psf.
Baltimore city, FIPS 24510, is home to 568,271 people near 39.3°N 76.6105°W. Its 25 psf ground snow load figure is the map value; 20 psf is what a roof is actually designed for.
Baltimore city's snowfall, most winters
28.5 in. a year: that's Baltimore city's NOAA 1991-2020 snowfall normal, measured at COLUMBIA 2.3 N, MD US (14.1 mi away). See the density guide.
Before you rely on Baltimore city's number
Treat the Baltimore city 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.