The Shannon 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
Partly cloudy
Mostly sunny
Partly cloudy
Mostly sunny
Mostly sunny
Mostly sunny
4.14 inches of rain fell in two days, the most for this week of the year since records began in 1987. The next wettest, 3.23 inches, fell in 2005.
Shannon’s center stands about 260 ft above sea level. Within three miles the land runs from 230 ft to 330 ft, a difference of 100 ft: gently rolling country.
Under the town center the state geologic map shows Demopolis chalk, from the Late Cretaceous, 66 to 100 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 64×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Chalk. Age: Late Cretaceous, 66 to 100 million years old. About 12 mi of the line.
Chalk, clay. Age: Late Cretaceous, 66 to 100 million years old. About 6 mi of the line.
Sand. Age: Late Cretaceous, 66 to 100 million years old. About 3 mi of the line.
Sand, clay, limestone. Age: Late Cretaceous, 66 to 100 million years old. About 2 mi of the line.
Sand, clay. Age: Late Cretaceous, 66 to 100 million years old. About 0.4 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 Shannon reaches Mobile Bay and the Gulf of America by way of Chiwapa Creek, Town Creek, the Tombigbee and the Mobile: about 410 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Shannon; river miles along the main stem, rounded.
Shannon has a humid subtropical climate. Summer afternoons average 92° in July; winter nights fall to about 32° in January. About 59 inches of rain fall in a normal year.
On November 14 Shannon normally reaches 65° and falls to 41°. The record high is 78°, in 1999; the record low 21°, in 2013. The most rain on this date, 2.55 in, fell in 2005.
Normals 1991–2020 and records since 1987 at Verona Experiment Station, 3 miles north-northwest. NOAA, through RCC-ACIS.
