The Kaskaskia 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.
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Partly cloudy; warmer
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86° on Nov. 14, 1999, the hottest reading for this week of the year since 1974. Next is 85° in 1989.
Kaskaskia’s center stands about 370 ft above sea level. Within three miles the land runs from 350 ft to 680 ft, a difference of 330 ft: rolling country. The highest named summit within 15 miles is Mertell Hill, about 770 ft, 12 miles west-southwest.
Under the town center the state geologic map shows Lower Pope Group (Aux Vases Sandstone through Glen Dean Limestone) (limestone, sandstone, shale), from the Middle Mississippian, 331 to 347 million years old.
The section below crosses 10 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 47×. 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, sandstone, shale. Age: Late Mississippian, 324 to 331 million years old. About 7 mi of the line.
Limestone, sandstone, shale. Age: Middle Mississippian, 331 to 347 million years old. About 5 mi of the line.
Limestone. Age: Carboniferous, 324 to 359 million years old. About 3 mi of the line.
Shale, sandstone. Age: Early Pennsylvanian, 315 to 324 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.
Limestone. Age: Carboniferous, 324 to 359 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. 4 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.
Kaskaskia has a hot-summer humid continental climate. Summer afternoons average 89° in July; winter nights fall to about 24° in January. About 43 inches of rain fall in a normal year, with about 4 inches of snow.
On November 14 Kaskaskia normally reaches 56° and falls to 37°. The record high is 86°, in 1999; the record low 9°, in 1986. The most rain on this date, 3.40 in, fell in 1993.
Normals 1991–2020 and records since 1974 at Kaskaskia River Navigation Lock, 5 miles north-northwest. NOAA, through RCC-ACIS.
