The Decatur 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
Mostly sunny
Mostly sunny
Partly cloudy
Partly cloudy
Partly cloudy
Showers likely
−5° on Nov. 12, 2019, the coldest reading for this week of the year since 1996. Next is −4° in 2014.
Decatur’s center stands about 1,070 ft above sea level. Within three miles the land runs from 1,030 ft to 1,320 ft, a difference of 290 ft: rolling country. The highest named summit within 15 miles is Blackbird Hill, about 1,400 ft, 6 miles north-northwest.
Under the town center the state geologic map shows Dakota Group (sandstone, shale), from the Early Cretaceous, 100 to 145 million years old.
The section below crosses 6 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 44×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Sandstone, shale. Age: Early Cretaceous, 100 to 145 million years old. About 12 mi of the line.
Shale, limestone. Age: Middle Pennsylvanian, 307 to 315 million years old. About 4 mi of the line.
Shale, limestone. Age: Carboniferous, 299 to 324 million years old. About 4 mi of the line.
Shale, siltstone. Age: Middle Pennsylvanian, 307 to 315 million years old. About 2 mi of the line.
Shale, sandstone, siltstone. Age: Early Pennsylvanian to Middle Pennsylvanian, 307 to 324 million years old. About 1 mi of the line.
Sandstone, shale. Age: Early Cretaceous to Late Cretaceous, 94 to 113 million years old. About 0.7 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 Decatur reaches the Gulf of America by way of Elm Creek, the Missouri and the Mississippi: about 1,850 river miles.
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 Decatur; river miles along the main stem, rounded.
Decatur has a hot-summer humid continental climate. Summer afternoons average 87° in July; winter nights fall to about 12° in January. About 28 inches of rain fall in a normal year.
On November 14 Decatur normally reaches 50° and falls to 27°. The record high is 75°, in 2025; the record low 2°, in 2014. The most rain on this date, 0.11 in, fell in 2008.
Normals 1991–2020 and records since 1996 at Tekamah Municipal Airport, 17 miles south-southeast. NOAA, through RCC-ACIS.
