The Magnolia 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.
23° on Nov. 13, 2019, the coldest reading for this week of the year since 1948. Next is 25° in 1963.
Magnolia’s center stands about 310 ft above sea level. Within three miles the land runs from 280 ft to 440 ft, a difference of 160 ft: gently rolling country.
Under the town center the state geologic map shows Citronelle formation (sand, gravel), 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, gravel. Age: Pliocene to Pleistocene, less than 5.3 million years old. About 20 mi of the line.
Clay, sand. Age: Miocene, 5.3 to 23 million years old. About 2 mi of the line.
Clay, silt, sand. Age: Pleistocene, less than 2.6 million years old. About 1 mi of the line.
Clay. Age: Holocene, less than 12,000 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.
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 Magnolia reaches Lake Pontchartrain and the Gulf of America by way of the Minnehaha, the Little Tangipahoa and the Tangipahoa: about 90 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Magnolia; river miles along the main stem, rounded.
Magnolia has a humid subtropical climate. Summer afternoons average 91° in July; winter nights fall to about 38° in January. About 61 inches of rain fall in a normal year.
On November 14 Magnolia normally reaches 69° and falls to 45°. The record high is 85°, in 1993; the record low 25°, in 1963. The most rain on this date, 3.02 in, fell in 1993.
Normals 1991–2020 and records since 1948 at Mccomb Airport, 3 miles north-northwest. NOAA, through RCC-ACIS.