The West Conshohocken 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
Sunny
Sunny
Mostly sunny
Mostly sunny
77° on Nov. 12, 2015, the hottest reading for this week of the year since 1948. Next is 76° in 2020.
West Conshohocken’s center stands about 200 ft above sea level. Within three miles the land runs from 40 ft to 480 ft, a difference of 440 ft: hilly country. The highest named summit within 15 miles is Diamond Rock Hill, about 700 ft, 10 miles west.
Under the town center the state geologic map shows Octoraro Formation (schist, phyllite), from the Paleozoic, 252 to 542 million years old.
The section below crosses 13 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 28×. 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.
Arkose. Age: Triassic, 202 to 252 million years old. About 4 mi of the line.
Mudstone. Age: Triassic, 202 to 252 million years old. About 3 mi of the line.
Argillite. Age: Triassic, 202 to 252 million years old. About 3 mi of the line.
Sand. Age: Miocene, 5.3 to 23 million years old. About 2 mi of the line.
Gneiss. Age: Precambrian. 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. 7 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 West Conshohocken reaches Delaware Bay and the Atlantic Ocean by way of Gulph Creek, the Schuylkill and the Delaware: about 80 river miles.
60 miles of the trip are on the Delaware.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of West Conshohocken; river miles along the main stem, rounded.
West Conshohocken has a humid subtropical climate. Summer afternoons average 89° in July; winter nights fall to about 23° in January. A normal year brings about 25 inches of snow; with the rain, that comes to about 51 inches of water.
On November 14 West Conshohocken normally reaches 57° and falls to 35°. The record high is 74°, in 1955; the record low 19°, in 1986. The most rain on this date, 0.70 in, fell in 2020.
Normals 1991–2020 and records since 1948 at Norristown, 3 miles north-northwest, 140 ft lower. NOAA, through RCC-ACIS.
