The Pylesville 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
Partly cloudy; warmer
Mostly sunny
Sunny
Partly cloudy
Mostly sunny
Mostly sunny
78° on Nov. 12, 1999, the hottest reading for this week of the year since 1936. Next is 77° in 1993.
Pylesville’s center stands about 390 ft above sea level. Within three miles the land runs from 320 ft to 720 ft, a difference of 400 ft: rolling country.
Under the town center the state geologic map shows Wissahickon Formation; Metagraywacke (metagraywacke, muscovite-schist), from the Proterozoic, 542 to 2,500 million years old.
The section below crosses 8 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 24×. 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, phyllite. Age: Paleozoic, 252 to 542 million years old. About 6 mi of the line.
Muscovite-schist. Age: Proterozoic, 542 to 2,500 million years old. About 5 mi of the line.
Metagraywacke, muscovite-schist. Age: Proterozoic, 542 to 2,500 million years old. About 4 mi of the line.
Gabbro. Age: Proterozoic to Paleozoic, 252 to 2,500 million years old. About 3 mi of the line.
Muscovite-gneiss. Age: Proterozoic, 542 to 2,500 million years old. About 2 mi of the line.
Gneiss, quartz-diorite, granodiorite. Age: Neoproterozoic to Middle Cambrian, 500 to 600 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. 2 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 Pylesville reaches Chesapeake Bay and the Atlantic Ocean by way of the Jacks Hole, Broad Creek and the Susquehanna: about 30 river miles.
Lake on the way: Lake Aldred.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Pylesville; river miles along the main stem, rounded.
Pylesville has a humid subtropical climate. Summer afternoons average 88° in July; winter nights fall to about 25° in January. About 48 inches of rain fall in a normal year.
On November 14 Pylesville normally reaches 56° and falls to 37°. The record high is 75°, in 1955; the record low 22°, in 2019. The most rain on this date, 1.02 in, fell in 1957.
Normals 1991–2020 and records since 1936 at Conowingo Dam, 11 miles east-southeast, 350 ft lower. NOAA, through RCC-ACIS.
