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.
Showers likely
Chance of showers
Mostly cloudy
Sunny
Mostly sunny
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 1,430 ft above sea level. Within three miles the land runs from 1,400 ft to 2,090 ft, a difference of 690 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 5 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 15 mi of the line.
Shale. Age: Late Devonian, 359 to 384 million years old. About 4 mi of the line.
Siltstone, shale. Age: Late Devonian, 359 to 384 million years old. About 2 mi of the line.
Sandstone, siltstone, shale. Age: Late Devonian, 359 to 384 million years old. About 2 mi of the line.
Sandstone, siltstone, shale. Age: Devonian to Carboniferous, 324 to 422 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.
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 the Allegheny, the Ohio and the Mississippi: about 2,190 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.
