The Folsom 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.
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81° on Nov. 15, 1993, the hottest reading for this week of the year since 1871. Next is 76° in 1955.
Folsom’s center stands about 120 ft above sea level. Within three miles the land runs from 0 ft to 280 ft, a difference of 280 ft: rolling country. The highest named summit within 15 miles is Hunting Hill, about 510 ft, 8 miles northwest.
Under the town center the state geologic map shows Pensauken and Bridgeton Formations, undifferentiated (sand), from the Miocene, 5.3 to 23 million years old.
The section below crosses 15 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 36×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Mica-schist. Age: Paleozoic, 252 to 542 million years old. About 6 mi of the line.
Sand. Age: Miocene, 5.3 to 23 million years old. About 3 mi of the line.
Sand. Age: Late Cretaceous, 72 to 84 million years old. About 3 mi of the line.
Sand. Age: Late Cretaceous, 84 to 87 million years old. About 3 mi of the line.
Gneiss. Age: Precambrian. About 2 mi of the line.
Sand, clay. Age: Late Cretaceous, 72 to 84 million years old. About 2 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale. 9 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 Folsom reaches Delaware Bay and the Atlantic Ocean by way of Little Crum Creek, Crum Creek and the Delaware: about 55 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Folsom; river miles along the main stem, rounded.
Folsom has a humid subtropical climate. Summer afternoons average 88° in July; winter nights fall to about 26° in January. A normal year brings about 23 inches of snow; with the rain, that comes to about 44 inches of water.
On November 14 Folsom normally reaches 56° and falls to 39°. The record high is 76°, in 1955; the record low 19°, in 1986. The most rain on this date, 2.64 in, fell in 1972.
Normals 1991–2020 and records since 1871 from the Philadelphia Area threaded record (Philadelphia International Airport, 6 miles east-southeast, 110 ft lower). NOAA, through RCC-ACIS.
