The Orwigsburg 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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78° on Nov. 15, 1993, the hottest reading for this week of the year since 1858. Next is 74° in 1902.
Orwigsburg’s center stands about 600 ft above sea level. Within three miles the land runs from 490 ft to 1,410 ft, a difference of 920 ft: steep hill country. The highest named summit within 15 miles is Bears Head, about 2,090 ft, 14 miles north.
The section below crosses 12 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 14×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Sandstone. Age: Carboniferous, 299 to 324 million years old. About 5 mi of the line.
Shale. Age: Ordovician, 445 to 487 million years old. About 4 mi of the line.
Sandstone. Age: Carboniferous, 299 to 324 million years old. About 3 mi of the line.
Black-shale. Age: Early Devonian to Middle Devonian, 384 to 422 million years old. About 3 mi of the line.
Shale. Age: Silurian, 422 to 445 million years old. About 2 mi of the line.
Sandstone, conglomerate. Age: Silurian, 422 to 445 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. 6 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 Orwigsburg reaches Delaware Bay and the Atlantic Ocean by way of Mahannon Creek, the Schuylkill and the Delaware: about 170 river miles.
110 miles of the trip are on the Schuylkill.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Orwigsburg; river miles along the main stem, rounded.
Orwigsburg has a hot-summer humid continental climate. Summer afternoons average 87° in July; winter nights fall to about 23° in January. About 45 inches of rain fall in a normal year.
On November 14 Orwigsburg normally reaches 54° and falls to 36°. The record high is 74°, in 1955; the record low 16°, in 1986. The most rain on this date, 1.37 in, fell in 1995.
Normals 1991–2020 and records since 1858 from the Reading Area threaded record (Reading 4 SW, 24 miles south-southeast, 280 ft lower). NOAA, through RCC-ACIS.
