The Semmes 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.
Mostly sunny
Mostly sunny; warmer
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5.72 inches of rain fell in two days, the most for this week of the year since records began in 1871. The next wettest, 5.59 inches, fell in 1914.
Semmes’s center stands about 250 ft above sea level. Within three miles the land runs from 140 ft to 270 ft, a difference of 130 ft: gently rolling country.
Under the town center the state geologic map shows Citronelle Formation (sand), from the Pliocene to Pleistocene, less than 5.3 million years old.
The section below crosses 4 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.
Sand. Age: Pliocene to Pleistocene, less than 5.3 million years old. About 10 mi of the line.
Sand. Age: Holocene, less than 12,000 years old. About 6 mi of the line.
Sand, clay. Age: Miocene to Pliocene, 2.6 to 23 million years old. About 5 mi of the line.
Sand, gravel. Age: Pliocene to Pleistocene, less than 5.3 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 Semmes reaches Mobile Bay and the Gulf of America by way of Red Creek, Eightmile Creek, Chickasaw Creek and the Mobile: about 25 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Semmes; river miles along the main stem, rounded.
Semmes has a humid subtropical climate. Summer afternoons average 91° in July; winter nights fall to about 41° in January. About 67 inches of rain fall in a normal year.
On November 14 Semmes normally reaches 70° and falls to 48°. The record high is 82°, in 2008; the record low 28°, in 1969. The most rain on this date, 1.55 in, fell in 1929.
Normals 1991–2020 and records since 1871 from the Mobile Area threaded record (Mobile Regional Airport, 6 miles south). NOAA, through RCC-ACIS.
