Sully County, SD Roof Snow Load - 28 psf

How much snow is too much for a roof in Sully County, SD?

Picture it, not just weigh it: 61.6 in. if it's fresh powder, 22.4 in. once it settles, or a mere 5.6 in. if it's ice. A meaningful design load. Most homes built to modern code handle it, but additions, carports, and flat-roofed sections are worth a second look.

Sully County at a glance

• Design roof snow load28 psf
• Ground snow load, ASCE 7 map40 psf
• National rank#301 of 2,758
• South Dakota rank#44 of 65
• Population1,468
• Annual snowfall, NOAA normal48.8 in.
• FIPS46119

How Sully County compares

28 psf ranks #301 of 2,758 US counties with a mapped snow load (top 11%) - and #44 of 65 in South Dakota. 28.2 psf is South Dakota's typical county figure - Sully County comes in 0.2 psf under it.

Population 1,468 (FIPS 46119), roughly 44.7223°N 100.1314°W. The 40 psf ground snow load ASCE 7-22 maps here becomes 28 psf once the code's own design factors are applied.

Typical snowfall in Sully County, SD

NOAA's 30-year normal for Sully County: 48.8 in. of snow a year, from the ONIDA 4 NW, SD US station. (fresh vs. packed vs. ice explains why.)

What this Sully County figure assumes

This is a county-level reference figure for a typical heated home built to Risk Category II (ordinary residential), on a partially exposed lot - the assumptions ASCE 7-22 itself treats as the default case. A steeper roof, a fully exposed hilltop lot, an unheated structure, or a higher risk category all change the actual number.

Sully County's permit office wants an address-specific figure, not this county average - the ASCE 7 Hazard Tool is free, takes under a minute, and outputs a PDF most reviewers accept. Details: the calculation guide.