The Corydon 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
Partly cloudy; warmer
Mostly sunny
Mostly sunny
Partly cloudy
Mostly sunny
Chance of showers
77° on Nov. 14, 1999, the hottest reading for this week of the year since 1902. Next is 74° in 2001.
Corydon’s center stands about 1,100 ft above sea level. Within three miles the land runs from 990 ft to 1,100 ft, a difference of 110 ft: gently rolling country.
Under the town center the state geologic map shows Upper Cherokee Group (shale, siltstone), from the Middle Pennsylvanian, 307 to 315 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.
Shale, limestone. Age: Middle Pennsylvanian, 307 to 315 million years old. About 12 mi of the line.
Shale, siltstone. Age: Middle Pennsylvanian, 307 to 315 million years old. About 11 mi of the line.
Shale, sandstone, siltstone. Age: Early Pennsylvanian to Middle Pennsylvanian, 307 to 324 million years old. About 0.6 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 Corydon reaches the Gulf of America by way of West Jackson Creek, Jackson Creek, the South Fork Chariton, the Chariton, the Missouri and the Mississippi: about 1,580 river miles.
Lake on the way: Rathbun Lake.
1,170 miles of the trip are on the Mississippi.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Corydon; river miles along the main stem, rounded.
Corydon has a hot-summer humid continental climate. Summer afternoons average 85° in July; winter nights fall to about 13° in January. About 40 inches of rain fall in a normal year.
On November 14 Corydon normally reaches 49° and falls to 29°. The record high is 77°, in 1999; the record low 4°, in 1916. The most rain on this date, 1.18 in, fell in 1902.
Normals 1991–2020 and records since 1902 at Allerton, 5 miles southwest. NOAA, through RCC-ACIS.
