The Colerain 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
Partly cloudy
Sunny
Partly cloudy
Mostly sunny
Mostly sunny
74° on Nov. 11, 2024, the hottest reading for this week of the year since 1978. Next is 72° in 1993.
Colerain’s center stands about 520 ft above sea level. Within three miles the land runs from 290 ft to 710 ft, a difference of 420 ft: hilly country. The highest named summit within 15 miles is Gap Hill, about 880 ft, 10 miles north-northeast.
Under the town center the state geologic map shows Peters Creek Schist (mica-schist, quartzite), from the Paleozoic, 252 to 542 million years old.
The section below crosses 7 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 31×. 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, quartzite. Age: Paleozoic, 252 to 542 million years old. About 7 mi of the line.
Mica-schist. Age: Paleozoic, 252 to 542 million years old. About 6 mi of the line.
Quartzite. Age: Cambrian, 487 to 542 million years old. About 3 mi of the line.
Limestone. Age: Cambrian to Ordovician, 445 to 542 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.
Quartzite, schist. Age: Cambrian, 487 to 542 million years old. About 1 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale. 1 smaller unit 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 Colerain reaches Chesapeake Bay and the Atlantic Ocean by way of Coopers Run, East Branch Octoraro Creek, Octoraro Creek and the Susquehanna: about 40 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Colerain; river miles along the main stem, rounded.
Colerain has a hot-summer humid continental climate. Summer afternoons average 85° in July; winter nights fall to about 22° in January. A normal year brings about 18 inches of snow; with the rain, that comes to about 48 inches of water.
On November 14 Colerain normally reaches 54° and falls to 33°. The record high is 72°, in 1993; the record low 15°, in 2022. The most rain on this date, 0.92 in, fell in 1995.
Normals 1991–2020 and records since 1978 at Octoraro Lake, 4 miles south-southeast, 260 ft lower. NOAA, through RCC-ACIS.
