The Southbury 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.
10° on Nov. 16, 1996, the coldest reading for this week of the year since 1937. Next is 14° in 1956.
Southbury’s center stands about 250 ft above sea level. Within three miles the land runs from 160 ft to 760 ft, a difference of 600 ft: hilly country. The highest named summit within 15 miles is Mount Tom, about 1,280 ft, 15 miles north-northwest.
Under the town center the state geologic map shows Portland Arkose (arkose, siltstone), from the Early Jurassic, 175 to 202 million years old.
The section below crosses 11 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 19×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Schist, granofels. Age: Early Ordovician, 471 to 487 million years old. About 8 mi of the line.
Gneiss, amphibolite. Age: Middle Ordovician, 459 to 471 million years old. About 7 mi of the line.
Arkose, siltstone. Age: Early Jurassic, 175 to 202 million years old. About 2 mi of the line.
Schist, granofels. Age: Early Ordovician to Middle Ordovician, 459 to 487 million years old. About 2 mi of the line.
Granofels. Age: Middle Ordovician, 459 to 471 million years old. About 2 mi of the line.
Schist. Age: Silurian to Devonian, 359 to 445 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. 5 smaller units 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 Southbury reaches Long Island Sound and the Atlantic Ocean by way of the Pomperaug and the Housatonic: about 30 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Southbury; river miles along the main stem, rounded.
Southbury has a hot-summer humid continental climate. Summer afternoons average 85° in July; winter nights fall to about 21° in January. A normal year brings about 49 inches of snow; with the rain, that comes to about 53 inches of water.
On November 14 Southbury normally reaches 51° and falls to 34°. The record high is 73°, in 1993; the record low 16°, in 1939. The most rain on this date, 2.42 in, fell in 1937.
Normals 1991–2020 and records since 1937 at Danbury, 12 miles west-southwest, 160 ft higher. NOAA, through RCC-ACIS.