The Piedmont 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
Sunny; warmer
Mostly sunny
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Mostly sunny; cooler
Partly cloudy
Chance of showers
−15° on Nov. 14, 1959, the coldest reading for this week of the year since 1888. Next is −13° in 1916.
Piedmont’s center stands about 3,500 ft above sea level. Within three miles the land runs from 3,310 ft to 4,790 ft, a difference of 1,480 ft: steep hill country. The highest named summit within 15 miles is Scruton Mountain, about 5,890 ft, 15 miles south-southwest.
Under the town center the state geologic map shows Terrace Deposits (coarse-detrital, clay), from the Quaternary, less than 2.6 million years old.
The section below crosses 18 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 8×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Coarse-detrital, fine-detrital. Age: Quaternary, less than 2.6 million years old. About 5 mi of the line.
Limestone, dolostone. Age: Late Devonian to Early Mississippian, 347 to 384 million years old. About 4 mi of the line.
Claystone, conglomerate, sandstone. Age: Early Cretaceous, 100 to 145 million years old. About 2 mi of the line.
Amphibolite, amphibole-schist, greenstone. Age: Paleoproterozoic, 1.6 to 2.5 billion years old. About 2 mi of the line.
Shale. Age: Late Cretaceous, 66 to 100 million years old. About 2 mi of the line.
Black-shale. Age: Late Cretaceous, 66 to 100 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. 12 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 Piedmont reaches the Gulf of America by way of Elk Creek, the Cheyenne, the Missouri and the Mississippi: about 2,500 river miles.
Lakes on the way: Lake Oahe, Lake Sharpe, Lake Francis Case and Lewis and Clark Lake.
1,170 miles of the trip are on the Mississippi.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Piedmont; river miles along the main stem, rounded.
Piedmont has a dry-winter hot-summer continental climate. Summer afternoons average 84° in July; winter nights fall to about 16° in January. A normal year brings about 54 inches of snow; with the rain, that comes to about 20 inches of water.
On November 14 Piedmont normally reaches 48° and falls to 27°. The record high is 79°, in 1894; the record low −15°, in 1959. The most rain on this date, 0.67 in, fell in 1956.
Normals 1991–2020 and records since 1888 from the Rapid City Downtown Area threaded record (Rapid City Wfo, 14 miles southeast, 120 ft lower). NOAA, through RCC-ACIS.
