The Potosi 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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Mostly sunny; warmer
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3° on Nov. 13, 2019, the coldest reading for this week of the year since 1893. Next is 8° in 1894.
Potosi’s center stands about 900 ft above sea level. Within three miles the land runs from 850 ft to 1,190 ft, a difference of 340 ft: rolling country. The highest named summit within 15 miles is Pruitt Mountain, about 1,600 ft, 14 miles south.
Under the town center the state geologic map shows Eminence Dolomite, Potosi Dolomite (dolostone), from the Cambrian, 487 to 497 million years old.
The section below crosses 3 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 30×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Dolostone. Age: Cambrian, 487 to 497 million years old. About 17 mi of the line.
Dolostone, shale, siltstone. Age: Cambrian, 487 to 497 million years old. About 5 mi of the line.
Dolostone. Age: Early Ordovician, 471 to 487 million years old. About 3 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 Potosi reaches the Gulf of America by way of Mine a Breton Creek, the Mineral Fork, the Big River, the Meramec and the Mississippi: about 1,260 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Potosi; river miles along the main stem, rounded.
Potosi has a hot-summer humid continental climate. Summer afternoons average 86° in July; winter nights fall to about 21° in January. A normal year brings about 12 inches of snow; with the rain, that comes to about 46 inches of water.
On November 14 Potosi normally reaches 55° and falls to 36°. The record high is 76°, in 1993; the record low 10°, in 2019. The most rain on this date, 4.20 in, fell in 1993.
Normals 1991–2020 and records since 1893 at Potosi 4 SW, 4 miles southwest, 280 ft higher. NOAA, through RCC-ACIS.
