The LaCoste 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.
24° on Nov. 14, 2018, the coldest reading for this week of the year since 1949. Next is 27° in 1970.
LaCoste’s center stands about 720 ft above sea level. Within three miles the land runs from 670 ft to 820 ft, a difference of 150 ft: gently rolling country. The highest named summit within 15 miles is Cedar Hill, about 1,200 ft, 15 miles north-northwest.
Under the town center the state geologic map shows Terrace deposits (sand), from the Pleistocene to Holocene, less than 2.6 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 44×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Mudstone. Age: Late Paleocene to Early Eocene, 48 to 59 million years old. About 10 mi of the line.
Gravel. Age: Late Pliocene to Pleistocene, less than 3.6 million years old. About 7 mi of the line.
Sand. Age: Pleistocene to Holocene, less than 2.6 million years old. About 5 mi of the line.
Black-shale. Age: Late Cretaceous, 66 to 72 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 LaCoste reaches the Gulf of America by way of Polecat Creek, the Medina, the San Antonio, the Guadalupe and the South Guadalupe: about 270 river miles.
210 miles of the trip are on the San Antonio.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of LaCoste; river miles along the main stem, rounded.
LaCoste has a hot desert climate. Summer afternoons average 97° in August; winter nights fall to about 41° in January. Barely 0.0 inches of rain fall in a normal year.
On November 14 LaCoste normally reaches 72° and falls to 49°. The record high is 88°, in 2025; the record low 24°, in 2018. The most rain on this date, 1.10 in, fell in 1959.
Normals 1991–2020 and records since 1949 at San Antonio Kelly Field Afb, 15 miles east-northeast. NOAA, through RCC-ACIS.