The Union Hill 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
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Partly cloudy
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75° on Nov. 14, 1999, the hottest reading for this week of the year since 1887. Next is 74° in 1989.
Union Hill’s center stands about 620 ft above sea level. Within three miles the land runs from 590 ft to 640 ft, a difference of 50 ft: nearly flat ground. The highest named summit within 15 miles is Pilot Hill, about 780 ft, 8 miles southeast.
Under the town center the state geologic map shows Silurian System undivided (dolostone, limestone), from the Silurian, 422 to 445 million years old.
The section below crosses 3 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 11 mi of the line.
Shale, limestone. Age: Late Ordovician, 445 to 454 million years old. About 9 mi of the line.
Shale, sandstone. Age: Early Pennsylvanian to Middle Pennsylvanian, 307 to 324 million years old. About 4 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 Union Hill reaches the Gulf of America by way of Granary Creek, the Mazon, the Illinois and the Mississippi: about 1,490 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 Union Hill; river miles along the main stem, rounded.
Union Hill has a hot-summer humid continental climate. Summer afternoons average 85° in July; winter nights fall to about 16° in January. A normal year brings about 21 inches of snow; with the rain, that comes to about 42 inches of water.
On November 14 Union Hill normally reaches 50° and falls to 33°. The record high is 75°, in 1999; the record low 5°, in 1986. The most rain on this date, 0.56 in, fell in 1985.
Normals 1991–2020 and records since 1887 at Kankakee Wwtp, 14 miles east. NOAA, through RCC-ACIS.
