The Randolph AFB 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.
21° on Nov. 14, 2018, the coldest reading for this week of the year since 1948. Next is 25° in 1969.
Randolph AFB’s center stands about 750 ft above sea level. Within three miles the land runs from 630 ft to 860 ft, a difference of 230 ft: rolling country. The highest named summit within 15 miles is Classen Hill, about 1,230 ft, 13 miles northwest.
Under the town center the state geologic map shows Leona Formation (coarse-detrital, fine-detrital), from the Pleistocene, less than 2.6 million years old.
The section below crosses 8 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 34×. 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 5 mi of the line.
Sand. Age: Pleistocene to Holocene, less than 2.6 million years old. About 5 mi of the line.
Coarse-detrital, fine-detrital. Age: Pleistocene, less than 2.6 million years old. About 4 mi of the line.
Limestone. Age: Early Cretaceous, 100 to 113 million years old. About 4 mi of the line.
Clay, siltstone-mudstone. Age: Late Cretaceous, 66 to 100 million years old. About 3 mi of the line.
Limestone. Age: Late Cretaceous, 66 to 100 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. 2 smaller units along the line are not listed.
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 Randolph AFB reaches the Gulf of America by way of Womans Hollow Creek, Martinez Creek, Cibolo Creek, the San Antonio, the Guadalupe and the South Guadalupe: about 210 river miles.
130 miles of the trip are on the San Antonio.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Randolph AFB; river miles along the main stem, rounded.
Randolph AFB has a hot desert climate. Summer afternoons average 96° in July; winter nights fall to about 41° in January. Barely 0.0 inches of rain fall in a normal year.
Normals 1991–2020 and records since 1948 at Randolph Afb, here. NOAA, through RCC-ACIS.