The Ballwin 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.
Sunny
Partly cloudy; warmer
Sunny
Sunny
Partly cloudy
Partly cloudy
Partly cloudy
3.43 inches of rain fell in two days, the most for this week of the year since records began in 1975. The next wettest, 3.01 inches, fell in 2003.
Ballwin’s center stands about 620 ft above sea level. Within three miles the land runs from 490 ft to 750 ft, a difference of 260 ft: rolling country. The highest named summit within 15 miles is Tavern Rock, about 880 ft, 11 miles west.
Under the town center the state geologic map shows Meramecian Series (limestone), from the Carboniferous, 324 to 359 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 38×. 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. Age: Carboniferous, 324 to 359 million years old. About 9 mi of the line.
Limestone. Age: Carboniferous, 324 to 359 million years old. About 6 mi of the line.
Clay, silt, sand. Age: Holocene, less than 12,000 years old. About 4 mi of the line.
Limestone. Age: Middle Ordovician to Late Ordovician, 445 to 471 million years old. About 2 mi of the line.
Limestone. Age: Middle Ordovician, 459 to 471 million years old. About 2 mi of the line.
Dolostone, sandstone, limestone. Age: Early Ordovician to Middle Ordovician, 459 to 487 million years old. About 0.5 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 Ballwin reaches the Gulf of America by way of Fishpot Creek, the Meramec and the Mississippi: about 1,160 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Ballwin; river miles along the main stem, rounded.
Ballwin has a hot-summer humid continental climate. Summer afternoons average 89° in July; winter nights fall to about 22° in January. A normal year brings about 8 inches of snow; with the rain, that comes to about 42 inches of water.
On November 14 Ballwin normally reaches 57° and falls to 36°. The record high is 83°, in 1999; the record low 10°, in 1986. The most rain on this date, 1.64 in, fell in 1993.
Normals 1991–2020 and records since 1975 at St Charles 7 SSW, 6 miles north-northeast, 170 ft lower. NOAA, through RCC-ACIS.
