The Great Falls 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.
Sunny
Sunny; warmer
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Mostly sunny
87° on Nov. 17, 1958, the hottest reading for this week of the year since 1896. Next is 85° in 1931.
Great Falls’s center stands about 470 ft above sea level. Within three miles the land runs from 280 ft to 550 ft, a difference of 270 ft: rolling country.
Under the town center the state geologic map shows Great Falls metagranite, from the Neoproterozoic to Cambrian, 487 to 1,000 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 51×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Metagranite, metadiorite. Age: Neoproterozoic to Cambrian, 487 to 1,000 million years old. About 12 mi of the line.
Metagranite. Age: Neoproterozoic to Cambrian, 487 to 1,000 million years old. About 6 mi of the line.
Granite. Age: Carboniferous to Permian, 252 to 359 million years old. About 2 mi of the line.
Metavolcanic, hornblende-gneiss, amphibolite. Age: Neoproterozoic to Ordovician, 445 to 1,000 million years old. About 2 mi of the line.
Metavolcanic. Age: Neoproterozoic to Cambrian, 487 to 1,000 million years old. About 1 mi of the line.
Age: Neoproterozoic to Cambrian, 487 to 1,000 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 Great Falls reaches the Atlantic Ocean by way of Rocky Creek, the Catawba, the Wateree, the Congaree, the Santee and the South Santee: about 230 river miles.
Lake on the way: Lib Pines Lake.
90 miles of the trip are on the Wateree.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Great Falls; river miles along the main stem, rounded.
Great Falls has a humid subtropical climate. Summer afternoons average 91° in July; winter nights fall to about 31° in January. About 45 inches of rain fall in a normal year.
On November 14 Great Falls normally reaches 64° and falls to 39°. The record high is 85°, in 1931; the record low 24°, in 2019. The most rain on this date, 2.00 in, fell in 1908.
Normals 1991–2020 and records since 1896 at Winnsboro, 17 miles southwest. NOAA, through RCC-ACIS.
