The Flat Rock 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
Mostly sunny; warmer
Mostly sunny
Partly cloudy
Mostly sunny
Mostly sunny
Mostly sunny
3° on Nov. 12, 2019, the coldest reading for this week of the year since 1895. Next is 11° in 1911.
Flat Rock’s center stands about 500 ft above sea level. Within three miles the land runs from 450 ft to 630 ft, a difference of 180 ft: gently rolling country. The highest named summit within 15 miles is Red Hill, about 680 ft, 14 miles southwest.
Under the town center the state geologic map shows Bond Formation (shale, sandstone, limestone), from the Late Pennsylvanian, 304 to 307 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 64×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Shale, sandstone, limestone. Age: Late Pennsylvanian, 304 to 307 million years old. About 14 mi of the line.
Shale, sandstone. Age: Carboniferous, 299 to 324 million years old. About 5 mi of the line.
Shale. Age: Late Pennsylvanian, 304 to 307 million years old. About 4 mi of the line.
Shale, limestone. Age: Late Pennsylvanian, 304 to 307 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.
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 Flat Rock reaches the Gulf of America by way of Brushy Creek, the Embarras, Big Bayou, the Wabash River Old Channel, the Old Channel Wabash, the Ohio and the Mississippi: about 1,230 river miles.
970 miles of the trip are on the Mississippi.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Flat Rock; river miles along the main stem, rounded.
Flat Rock has a hot-summer humid continental climate. Summer afternoons average 88° in July; winter nights fall to about 20° in January. About 46 inches of rain fall in a normal year.
On November 14 Flat Rock normally reaches 54° and falls to 34°. The record high is 71°, in 1902; the record low 13°, in 2019. The most rain on this date, 1.00 in, fell in 2024.
Normals 1991–2020 and records since 1895 at Robinson, 9 miles northwest. NOAA, through RCC-ACIS.
