The Allegany 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.
Chance of showers
Mostly cloudy
Mostly cloudy
Sunny
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Partly cloudy
Partly cloudy
76° on Nov. 11, 2020, the hottest reading for this week of the year since 1909. Next is 71° in 2012.
Allegany’s center stands about 1,480 ft above sea level. Within three miles the land runs from 1,400 ft to 2,100 ft, a difference of 700 ft: hilly country. The highest named summit within 15 miles is Hartzfelt Mountain, about 2,430 ft, 5 miles south-southeast.
Under the town center the state geologic map shows Conneaut Group, undivided (shale, sandstone), from the Late Devonian, 359 to 384 million years old.
The section below crosses 6 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 19×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Shale, sandstone. Age: Late Devonian, 359 to 384 million years old. About 13 mi of the line.
Shale. Age: Late Devonian, 359 to 384 million years old. About 5 mi of the line.
Sandstone, siltstone, shale. Age: Late Devonian, 359 to 384 million years old. About 3 mi of the line.
Sandstone, siltstone, shale. Age: Devonian to Carboniferous, 324 to 422 million years old. About 2 mi of the line.
Shale, siltstone, sandstone. Age: Late Devonian, 359 to 384 million years old. About 0.5 mi of the line.
Siltstone, shale. Age: Late Devonian, 359 to 384 million years old. About 0.5 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale.
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 Allegany reaches the Gulf of America by way of Fivemile Creek, the Allegheny, the Ohio and the Mississippi: about 2,200 river miles.
Lake on the way: Allegheny Reservoir.
970 miles of the trip are on the Ohio.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Allegany; river miles along the main stem, rounded.
Allegany has a warm-summer humid continental climate. Summer afternoons average 80° in July; winter nights fall to about 13° in January. A normal year brings about 65 inches of snow; with the rain, that comes to about 41 inches of water.
Normals 1991–2020 and records since 1909 at Olean, 2 miles east-southeast. NOAA, through RCC-ACIS.
