SnowLoadCheck

Nantucket County, MA Roof Snow Load - 20 psf

Nantucket County, MA: your roof's ASCE 7 snow number, in plain English

Moderate
20 psf

Nantucket County's roofs are built to hold 20 psf of snow, the ASCE 7-22 figure a permit reviewer checks first. Flat and low-pitch roofs in Nantucket County are actually governed by ASCE 7's §7.3.4 minimum of 20 psf, not the 17.5 psf the ground-load formula alone would produce.

In depth, not weight: that's roughly 44 inches of fresh, light snow, 16 inches of old, settled snow, or as little as 4 inches of solid ice - snow that heavy is rare here but ice from a freeze-thaw cycle adds up far faster than the depth suggests. A meaningful design load. Most homes built to modern code handle it, but additions, carports, and flat-roofed sections are worth a second look.

Nantucket County, MA: quick facts

Nantucket County by the numbers

Nationally that's #1,034 out of 2,758 rated counties, the top 37%; within Massachusetts alone, Nantucket County ranks #14 of 14. 27.6 psf is Massachusetts's typical county figure - Nantucket County comes in 7.6 psf under it.

Nantucket County, FIPS 25019, is home to 14,670 people near 41.2934°N 70.1022°W. Its 25 psf ground snow load figure is the map value; 20 psf is what a roof is actually designed for.

Nantucket County's snowfall, most winters

25.3 in. a year: that's Nantucket County's NOAA 1991-2020 snowfall normal, measured at EDGARTOWN, MA US (22.5 mi away). See the density guide.

Before you rely on Nantucket County's number

Treat the Nantucket County figure as a starting point, not a final answer: it assumes standard occupancy, a heated structure and a moderately sheltered site, per ASCE 7-22's own defaults. Exposed terrain, an unheated building or a steeper roof all shift the real number.

For a real application, skip the county number and go straight to the ASCE 7 Hazard Tool - enter your coordinates and it returns a site-specific figure a plan reviewer will recognize. Details: the calculation guide.