San Francisco County, CA Roof Snow Load - Case Study Area
San Francisco County, CA: missing from the map query
The ASCE 7 map service returned no feature at San Francisco County's survey point - this happens for a small number of shoreline counties (386 nationally are unrated for one reason or another) whose reference point falls just outside every mapped polygon. Not the same thing as a Case Study area - the map likely has a real value a few hundred feet away.
San Francisco County, FIPS 06075, population 827,526.
San Francisco County, CA: quick facts
- Population827,526
- Annual snowfall, NOAA normal0 in.
- FIPS06075
San Francisco County: average annual snowfall
San Francisco County sees about 0 in. of snow most winters, per the MUIR WOODS, CA US station's 1991-2020 NOAA normal. 27.9 mi is a real gap between San Francisco County and its nearest reporting station, so local snowfall can diverge from this figure, especially near elevation changes. See the density guide.
Read this before you use San Francisco County's figure
The figure above assumes the case ASCE 7-22 treats as typical: a heated, ordinary-occupancy home on a partially exposed site. Change any of those - exposure, heating, roof pitch, occupancy category - and the real design number moves.
A building permit needs the number at your exact address, not the county average - the free ASCE 7 Hazard Tool returns that from your coordinates in about a minute and produces a PDF a plan reviewer will accept. (How this figure is calculated.)