The Manchaca 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.
Chance of showers
Showers likely
Chance of showers
Mostly sunny; warmer
Mostly cloudy
Partly cloudy
Partly cloudy
24° on Nov. 14, 2018, the coldest reading for this week of the year since 1942. Next is 25° in 2014.
Manchaca’s center stands about 690 ft above sea level. Within three miles the land runs from 600 ft to 810 ft, a difference of 210 ft: rolling country. The highest named summit within 15 miles is Chalk Knob, about 1,180 ft, 14 miles northwest.
The section below crosses 9 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 27×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Limestone, marlstone. Age: Early Cretaceous, 100 to 145 million years old. About 6 mi of the line.
Clay, siltstone-mudstone. Age: Late Cretaceous, 66 to 100 million years old. About 5 mi of the line.
Limestone. Age: Early Cretaceous, 100 to 113 million years old. About 4 mi of the line.
Limestone, carbonate. Age: Late Cretaceous, 66 to 72 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.
Gravel. 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. 3 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 Manchaca reaches the Gulf of America by way of Bear Creek, Onion Creek and the Colorado: about 300 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Manchaca; river miles along the main stem, rounded.
Manchaca has a humid subtropical climate. Summer afternoons average 97° in August; winter nights fall to about 38° in January. About 36 inches of rain fall in a normal year.
On November 14 Manchaca normally reaches 72° and falls to 47°. The record high is 89°, in 2020; the record low 24°, in 2018. The most rain on this date, 0.87 in, fell in 1998.
Normals 1991–2020 and records since 1942 from the Austin-Bergstrom Airport Area threaded record (Austin-Camp Mabry, 14 miles north-northeast). NOAA, through RCC-ACIS.
