The Duncanville 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
Partly cloudy
Sunny
Mostly cloudy
Partly cloudy
Partly cloudy
89° on Nov. 14, 1989, the hottest reading for this week of the year since 1913. Next is 88° in 2025.
Duncanville’s center stands about 730 ft above sea level. Within three miles the land runs from 600 ft to 770 ft, a difference of 170 ft: gently rolling country.
Under the town center the state geologic map shows Austin Chalk (marlstone, chalk), from the Late Cretaceous, 66 to 100 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 42×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Marlstone, chalk. Age: Late Cretaceous, 66 to 100 million years old. About 16 mi of the line.
Black-shale, siltstone. Age: Late Cretaceous, 66 to 100 million years old. About 5 mi of the line.
Sand. Age: Pleistocene to Holocene, less than 2.6 million years old. About 1 mi of the line.
Fine-detrital, coarse-detrital. 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 Duncanville reaches Galveston Bay and the Gulf of America by way of Tenmile Creek and the Trinity: about 450 river miles.
Lake on the way: Woodlands Golf Course Lake.
230 miles of the trip are on the Trinity.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Duncanville; river miles along the main stem, rounded.
Duncanville has a humid subtropical climate. Summer afternoons average 97° in July; winter nights fall to about 38° in January. About 38 inches of rain fall in a normal year, with about 2 inches of snow.
On November 14 Duncanville normally reaches 68° and falls to 48°. The record high is 89°, in 1989; the record low 21°, in 1940. The most rain on this date, 2.05 in, fell in 1994.
Normals 1991–2020 and records since 1913 from the Dallas Area threaded record (Dallas Faa Airport, 14 miles north-northeast, 250 ft lower). NOAA, through RCC-ACIS.
