The Granby plate. Relief from Copernicus GLO-30; rivers and lakes from USGS NHD; watersheds from the USGS Watershed Boundary Dataset; roads and city limits from Census TIGER 2024.
Partly cloudy
Mostly sunny; warmer
Partly cloudy
Mostly sunny
Mostly sunny
Mostly sunny
Mostly sunny
72° on Nov. 11, 2020, the hottest reading for this week of the year since 1926. Next is 71° in 2022.
Granby’s center stands about 320 ft above sea level. Within three miles the land runs from 210 ft to 580 ft, a difference of 370 ft: rolling country. The highest named summit within 15 miles is Spruce Hill, about 1,480 ft, 15 miles west-northwest.
Under the town center the state geologic map shows Portland Formation (conglomerate, arkose), from the Early Jurassic, 175 to 202 million years old.
The section below crosses 7 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 16×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Conglomerate, arkose. Age: Early Jurassic, 175 to 202 million years old. About 9 mi of the line.
Arkose, siltstone. Age: Early Jurassic, 175 to 202 million years old. About 6 mi of the line.
Gneiss. Age: Neoproterozoic, 610 to 616 million years old. About 4 mi of the line.
Arkose, siltstone, sandstone. Age: Late Triassic, 202 to 237 million years old. About 2 mi of the line.
Siltstone, sandstone. Age: Early Jurassic, 175 to 202 million years old. About 1 mi of the line.
Schist, phyllite. Age: Early Devonian, 394 to 422 million years old. About 1 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale. 1 smaller unit along the line are not listed.
Heights from Copernicus GLO-90 (a surface model: it includes buildings and tree canopy); summits from USGS GNIS; rivers from USGS NHDPlus HR; rock from the USGS State Geologic Map Compilation.
A raindrop that lands in Granby reaches Long Island Sound and the Atlantic Ocean by way of Stony Brook and the Connecticut: about 95 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Granby; river miles along the main stem, rounded.
Granby has a hot-summer humid continental climate. Summer afternoons average 85° in July; winter nights fall to about 15° in January. About 45 inches of rain fall in a normal year.
On November 14 Granby normally reaches 51° and falls to 31°. The record high is 66°, in 2011; the record low 11°, in 2019. The most rain on this date, 1.44 in, fell in 1995.
Normals 1991–2020 and records since 1926 from the Westfield Area threaded record (Westfield-Barnes Regional Airport, 12 miles west-southwest). NOAA, through RCC-ACIS.
