Howard County, MD Roof Snow Load - 20 psf
How much snow is too much for a roof in Howard County, MD?
20 psf: that's what ASCE 7-22 requires a typical heated home's roof in Howard County to carry. 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.
Picture it, not just weigh it: 44 in. if it's fresh powder, 16 in. once it settles, or a mere 4 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.
Howard County, MD: quick facts
- Design roof snow load20 psf
- Ground snow load, ASCE 7 map25 psf
- National rank#557 of 2,758
- Maryland rank#8 of 21
- Population339,668
- Annual snowfall, NOAA normal28.5 in.
- FIPS24027
How Howard County compares
20 psf ranks #557 of 2,758 US counties with a mapped snow load (top 20%) - and #8 of 21 in Maryland. 20.1 psf is Maryland's typical county figure - Howard County comes in 0.1 psf under it.
Population 339,668 (FIPS 24027), roughly 39.2523°N 76.9244°W. The 25 psf ground snow load ASCE 7-22 maps here becomes 20 psf once the code's own design factors are applied.
Typical snowfall in Howard County, MD
NOAA's 30-year normal for Howard County: 28.5 in. of snow a year, from the COLUMBIA 2.3 N, MD US station. (fresh vs. packed vs. ice explains why.)
What this Howard 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.
Howard 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. See the methodology guide.