Modoc County, CA Roof Snow Load - 15 psf
What ASCE 7 says about snow load in Modoc County
That's Modoc County's design roof snow load per ASCE 7-22, for a typical heated single-family home - the number a permit reviewer starts from. The physics-based figure alone would be 10.5 psf, but ASCE 7's own low-slope minimum (§7.3.4) sets a floor of 15 psf for flat and low-pitch roofs here, which is the number that actually governs.
Converted to something you can actually eyeball on a roof: about 33 in. of fresh powder, 12 in. once it settles and packs down, or just 3 in. if it's turned to 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.
Modoc County, CA: quick facts
- Design roof snow load15 psf
- Ground snow load, ASCE 7 map15 psf
- National rank#1,570 of 2,758
- California rank#2 of 41
- Population8,491
- Annual snowfall, NOAA normal22.2 in.
- FIPS06049
Where Modoc County's figure sits nationally
Out of 2,758 rated US counties, Modoc County sits at #1,570, the top 57% nationally - #2 of 41 within California. 1.1 psf is California's typical county figure - Modoc County beats it by 13.9 psf.
Near 41.5929°N 120.7184°W, FIPS 06049: Modoc County counts 8,491 residents and a 15 psf map value, which the code's own factors turn into 15 psf.
How much it actually snows in Modoc County
Most winters bring Modoc County roughly 22.2 in. of snow - NOAA's normal at CEDARVILLE, CA US, 28.2 mi off. Worth noting: the nearest station reporting snowfall normals sits 28.2 mi from Modoc County's center, so treat this as a regional figure rather than an exact one. (fresh vs. packed vs. ice explains why.)
Read this before you rely on it
Modoc County's number above is ASCE 7-22's default case, not a custom calculation: ordinary residential occupancy, heated, sited on ground that's neither fully sheltered nor fully exposed. Any one of those changing - pitch, exposure, heating, occupancy - moves the real figure.
Nothing here substitutes for an address-level number. Get one free, in about a minute, from the ASCE 7 Hazard Tool using your own coordinates rather than Modoc County's county-wide figure. Details: the calculation guide.