Washington County, ID Roof Snow Load - Case Study Area
What "Case Study" means for Washington County
ASCE 7's own snow load map has no single figure for Washington County: the terrain is complex enough that the code (§7.2) requires an elevation-specific study rather than a county-wide value. That is the map being accurate, not a data gap.
FIPS 16087, population 11,539. 386 US counties get this same case-study treatment; Washington County is one of them.
Washington County, ID: quick facts
- Population11,539
- Annual snowfall, NOAA normal15.4 in.
- FIPS16087
Washington County: average annual snowfall
Washington County sees about 15.4 in. of snow most winters, per the MALHEUR BRANCH EXP STN, OR US station's 1991-2020 NOAA normal. Worth noting: the nearest station reporting snowfall normals sits 34.3 mi from Washington County's center, so treat this as a regional figure rather than an exact one. See the density guide.
Read this before you use Washington 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. See the methodology guide.