The Richardson 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.
87° on Nov. 15, 2025, the hottest reading for this week of the year since 1946. Next is 84° in 2013.
Richardson’s center stands about 640 ft above sea level. Within three miles the land runs from 550 ft to 690 ft, a difference of 140 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 2 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 61×. 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 18 mi of the line.
Fine-detrital, coarse-detrital. Age: Holocene, less than 12,000 years old. About 3 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 Richardson reaches Galveston Bay and the Gulf of America by way of Duck Creek, the East Fork Trinity and the Trinity: about 460 river miles.
Lake on the way: Woodlands Golf Course Lake.
220 miles of the trip are on the Trinity.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Richardson; river miles along the main stem, rounded.
Richardson has a humid subtropical climate. Summer afternoons average 95° in August; winter nights fall to about 36° in January. About 42 inches of rain fall in a normal year.
Normals 1991–2020 and records since 1946 at Richardson, 3 miles north-northwest. NOAA, through RCC-ACIS.