Big Horn County, WY Roof Snow Load - 15 psf
What ASCE 7 says about snow load in Big Horn County
That's Big Horn County's design roof snow load per ASCE 7-22, for a typical heated single-family home - the number a permit reviewer starts from. ASCE 7's low-slope-roof minimum (§7.3.4) raises the governing figure to 15 psf - higher than the 10.5 psf the ground-load formula alone would give, and the code says use the larger one.
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.
Big Horn County in numbers
- Design roof snow load15 psf
- Ground snow load, ASCE 7 map15 psf
- National rank#1,536 of 2,758
- Wyoming rank#14 of 18
- Population12,084
- Annual snowfall, NOAA normal20.1 in.
- FIPS56003
Where Big Horn County's figure sits nationally
Out of 2,758 rated US counties, Big Horn County sits at #1,536, the top 56% nationally - #14 of 18 within Wyoming. Wyoming counties average 17.5 psf; Big Horn County runs 2.5 psf lower than that.
Near 44.5251°N 107.9948°W, FIPS 56003: Big Horn County counts 12,084 residents and a 15 psf map value, which the code's own factors turn into 15 psf.
How much it actually snows in Big Horn County
Most winters bring Big Horn County roughly 20.1 in. of snow - NOAA's normal at BASIN, WY US, 10.2 mi off. (fresh vs. packed vs. ice explains why.)
Read this before you rely on it
Big Horn 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 Big Horn County's county-wide figure. (How this figure is calculated.)