The Charlestown 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.
78° on Nov. 15, 1993, the hottest reading for this week of the year since 1893. Next is 77° in 1973.
Charlestown’s center stands about 290 ft above sea level. Within three miles the land runs from 120 ft to 670 ft, a difference of 550 ft: hilly country. The highest named summit within 15 miles is Chestnut Hill, about 1,060 ft, 14 miles northwest.
Under the town center the state geologic map shows Felsic and intermediate gneiss (muscovite-gneiss), from the Precambrian.
The section below crosses 9 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.
Mudstone. Age: Triassic, 202 to 252 million years old. About 6 mi of the line.
Muscovite-gneiss. Age: Precambrian. About 5 mi of the line.
Arkose. Age: Triassic, 202 to 252 million years old. About 3 mi of the line.
Schist, phyllite. Age: Paleozoic, 252 to 542 million years old. About 3 mi of the line.
Argillite. Age: Triassic, 202 to 252 million years old. About 2 mi of the line.
Dolostone. Age: Cambrian, 487 to 542 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. 3 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 Charlestown reaches Delaware Bay and the Atlantic Ocean by way of Pickering Creek, the Schuylkill and the Delaware: about 100 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 Charlestown; river miles along the main stem, rounded.
Charlestown has a hot-summer humid continental climate. Summer afternoons average 88° in July; winter nights fall to about 23° in January. About 45 inches of rain fall in a normal year.
On November 14 Charlestown normally reaches 56° and falls to 35°. The record high is 75°, in 1955; the record low 19°, in 1950. The most rain on this date, 2.56 in, fell in 1972.
Normals 1991–2020 and records since 1893 at Phoenixville 1 E, 4 miles east-northeast, 150 ft lower. NOAA, through RCC-ACIS.