The Calhoun 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.
4.34 inches of rain fell in two days, the most for this week of the year since records began in 1899. The next wettest, 3.01 inches, fell in 1940.
Calhoun Falls’s center stands about 540 ft above sea level. Within three miles the land runs from 450 ft to 610 ft, a difference of 160 ft: gently rolling country. The highest named summit within 15 miles is Parsons Mountain, about 840 ft, 13 miles east.
Under the town center the state geologic map shows Biotite quartz-plagioclase gneiss (biotite-gneiss), from the Neoproterozoic to Paleozoic, 252 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.
Biotite-gneiss. Age: Neoproterozoic to Paleozoic, 252 to 1,000 million years old. About 7 mi of the line.
Mica-schist. Age: Neoproterozoic to Cambrian, 487 to 1,000 million years old. About 6 mi of the line.
Metagranite. Age: Neoproterozoic to Devonian, 359 to 1,000 million years old. About 4 mi of the line.
Gneiss. Age: Ordovician to Silurian, 422 to 487 million years old. About 3 mi of the line.
Gabbro. Age: Silurian to Devonian, 359 to 445 million years old. About 1 mi of the line.
Phyllonite, schist. Age: Paleozoic, 252 to 542 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 Calhoun Falls reaches the Atlantic Ocean by way of Sawney Creek, the Little River and the Savannah: about 270 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Calhoun Falls; river miles along the main stem, rounded.
Calhoun Falls has a humid subtropical climate. Summer afternoons average 92° in July; winter nights fall to about 32° in January. About 47 inches of rain fall in a normal year.
On November 14 Calhoun Falls normally reaches 65° and falls to 40°. The record high is 83°, in 1924; the record low 21°, in 1984. The most rain on this date, 1.66 in, fell in 1972.
Normals 1991–2020 and records since 1899 at Calhoun Falls, here. NOAA, through RCC-ACIS.