Macon County, MO Roof Snow Load - 20 psf
What ASCE 7 says about snow load in Macon County
That's Macon County's design roof snow load per ASCE 7-22, for a typical heated single-family home - the number a permit reviewer starts from. §7.3.4's low-slope minimum of 20 psf is what actually governs on a flat or low-pitch roof here - higher than the 14 psf the base ground-load formula gives.
Converted to something you can actually eyeball on a roof: about 44 in. of fresh powder, 16 in. once it settles and packs down, or just 4 in. if it's turned to ice. This is a meaningful design load - most modern-code homes handle it fine, though an addition, a carport or a flat-roofed section can be a weak spot.
Already snow on the roof in Macon County?
Macon County, MO: quick facts
- Design roof snow load20 psf
- Ground snow load, ASCE 7 map20 psf
- National rank#1,024 of 2,758
- Missouri rank#50 of 115
- Population15,177
- Annual snowfall, NOAA normal18.9 in.
- FIPS29121
Where Macon County's figure sits nationally
Out of 2,758 rated US counties, Macon County sits at #1,024, the top 37% nationally - #50 of 115 within Missouri. Missouri counties average 18.6 psf; Macon County runs 1.4 psf higher than that.
Near 39.8298°N 92.5643°W, FIPS 29121: Macon County counts 15,177 residents and a 20 psf map value, which the code's own factors turn into 20 psf.
How much it actually snows in Macon County
Most winters bring Macon County roughly 18.9 in. of snow - NOAA's normal at BROOKFIELD, MO US, 26.7 mi off. That station is far enough away (26.7 mi) that local snowfall - especially at a different elevation or near a lake - can run noticeably higher or lower than this figure. (fresh vs. packed vs. ice explains why.)
Read this before you rely on it
Macon 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 Macon County's county-wide figure. (How this figure is calculated.)