The Glen St. Mary 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.
5.46 inches of rain fell in two days, the most for this week of the year since records began in 1919. The next wettest, 2.99 inches, fell in 2019.
Glen St. Mary’s center stands about 140 ft above sea level. Within three miles the land runs from 100 ft to 170 ft, a difference of 70 ft: gently rolling country.
Under the town center the state geologic map shows Undifferentiated sediments (sand, clay), 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, clay. Age: Pliocene to Pleistocene, less than 5.3 million years old. About 17 mi of the line.
Sand. Age: Late Pliocene, 2.6 to 3.6 million years old. About 3 mi of the line.
Sand. Age: Pleistocene, less than 2.6 million years old. About 2 mi of the line.
Sand. Age: Pleistocene, less than 2.6 million years old. About 2 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 Glen St. Mary reaches the Atlantic Ocean by way of the South Prong Saint Marys and the Saint Marys: about 120 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Glen St. Mary; river miles along the main stem, rounded.
Glen St. Mary has a humid subtropical climate. Summer afternoons average 93° in July; winter nights fall to about 40° in January. About 53 inches of rain fall in a normal year.
On November 14 Glen St. Mary normally reaches 75° and falls to 49°. The record high is 85°, in 2018; the record low 27°, in 1963. The most rain on this date, 2.57 in, fell in 1949.
Normals 1991–2020 and records since 1919 at Glen St Mary 1 W, here. NOAA, through RCC-ACIS.