Grafton County, NH Roof Snow Load - Case Study Area
Grafton County, NH: no map figure, on purpose
ASCE 7's own snow load map has no single figure for Grafton 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 33009, population 93,045. 386 US counties get this same case-study treatment; Grafton County is one of them.
Grafton County, NH: quick facts
- Population93,045
- Annual snowfall, NOAA normal67.2 in.
- FIPS33009
Grafton County: average annual snowfall
Grafton County sees about 67.2 in. of snow most winters, per the GLENCLIFF 2, NH US station's 1991-2020 NOAA normal. See the density guide.
Read this before you use Grafton 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. Details: the calculation guide.