Lassen County, CA Roof Snow Load - 15 psf
How much snow is too much for a roof in Lassen County, CA?
15 psf: that's what ASCE 7-22 requires a typical heated home's roof in Lassen County to carry. §7.3.4's low-slope minimum of 15 psf is what actually governs on a flat or low-pitch roof here - higher than the 10.5 psf the base ground-load formula gives.
Picture it, not just weigh it: 33 in. if it's fresh powder, 12 in. once it settles, or a mere 3 in. if it's ice. Modern-code homes carry a load like this without issue; an older addition, a carport, or any flat-roofed section is where it is worth checking first.
Already snow on the roof in Lassen County?
Lassen County, CA: quick facts
- Design roof snow load15 psf
- Ground snow load, ASCE 7 map15 psf
- National rank#1,433 of 2,758
- California rank#1 of 41
- Population28,340
- Annual snowfall, NOAA normal45.1 in.
- FIPS06035
How Lassen County compares
15 psf ranks #1,433 of 2,758 US counties with a mapped snow load (top 52%) - and #1 of 41 in California. California counties average 1.1 psf; Lassen County runs 13.9 psf higher than that.
Population 28,340 (FIPS 06035), roughly 40.7153°N 120.6212°W. The 15 psf ground snow load ASCE 7-22 maps here becomes 15 psf once the code's own design factors are applied.
Typical snowfall in Lassen County, CA
NOAA's 30-year normal for Lassen County: 45.1 in. of snow a year, from the ADIN RS, CA US station. Worth noting: the nearest station reporting snowfall normals sits 37.1 mi from Lassen County's center, so treat this as a regional figure rather than an exact one. (fresh vs. packed vs. ice explains why.)
What this Lassen 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.
Lassen 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. Details: the calculation guide.