The Wilmington 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.
Mostly sunny
Sunny; warmer
Sunny
Sunny
Partly cloudy
Partly cloudy
Partly cloudy
74° on Nov. 14, 1989, the hottest reading for this week of the year since 1943. Next is 74° in 2020.
Wilmington’s center stands about 550 ft above sea level. Within three miles the land runs from 510 ft to 620 ft, a difference of 110 ft: gently rolling country.
Under the town center the state geologic map shows Maquoketa Formation or Group (shale, limestone), from the Late Ordovician, 445 to 454 million years old.
The section below crosses 5 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.
Dolostone, limestone. Age: Silurian, 422 to 445 million years old. About 10 mi of the line.
Shale, sandstone. Age: Early Pennsylvanian to Middle Pennsylvanian, 307 to 324 million years old. About 9 mi of the line.
Shale, limestone. Age: Late Ordovician, 445 to 454 million years old. About 4 mi of the line.
Dolostone, limestone. Age: Late Ordovician, 447 to 459 million years old. About 1 mi of the line.
Shale, sandstone, coal. Age: Middle Pennsylvanian to Late Pennsylvanian, 304 to 315 million years old. About 0.3 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 Wilmington reaches the Gulf of America by way of the Kankakee, the Illinois and the Mississippi: about 1,470 river miles.
Lake on the way: Peoria Lake.
1,190 miles of the trip are on the Mississippi.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Wilmington; river miles along the main stem, rounded.
Wilmington has a hot-summer humid continental climate. Summer afternoons average 84° in July; winter nights fall to about 17° in January. A normal year brings about 17 inches of snow; with the rain, that comes to about 38 inches of water.
On November 14 Wilmington normally reaches 49° and falls to 33°. The record high is 74°, in 1989; the record low 6°, in 1986. The most rain on this date, 1.50 in, fell in 1972.
Normals 1991–2020 and records since 1943 at Joliet Brandon Road Lock/Dam, 14 miles north. NOAA, through RCC-ACIS.
