The Chain-O-Lakes 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.
4° on Nov. 17, 1959, the coldest reading for this week of the year since 1893. Next is 6° in 2019.
Chain-O-Lakes’s center stands about 750 ft above sea level. Within three miles the land runs from 710 ft to 840 ft, a difference of 130 ft: gently rolling country. The highest named summit within 15 miles is Reeves Hill, about 900 ft, 10 miles south.
Under the town center the state geologic map shows Ellsworth Shale, from the Devonian to Carboniferous, 324 to 422 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 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. Age: Devonian to Carboniferous, 324 to 422 million years old. About 17 mi of the line.
Shale. Age: Late Devonian, 359 to 384 million years old. About 7 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 Chain-O-Lakes reaches the Gulf of America by way of the Kankakee, the Illinois and the Mississippi: about 1,610 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 Chain-O-Lakes; river miles along the main stem, rounded.
Chain-O-Lakes has a hot-summer humid continental climate. Summer afternoons average 83° in July; winter nights fall to about 17° in January. A normal year brings about 64 inches of snow; with the rain, that comes to about 39 inches of water.
On November 14 Chain-O-Lakes normally reaches 48° and falls to 32°. The record high is 71°, in 1971; the record low 10°, in 1986. The most rain on this date, 1.50 in, fell in 1957.
Normals 1991–2020 and records since 1893 from the South Bend Area threaded record (South Bend Airport, 4 miles east). NOAA, through RCC-ACIS.