The Irene 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.
79° on Nov. 15, 2025, the hottest reading for this week of the year since 1897. Next is 78° in 1953.
Irene’s center stands about 1,400 ft above sea level. Within three miles the land runs from 1,310 ft to 1,520 ft, a difference of 210 ft: rolling country.
Under the town center the state geologic map shows Niobrara Formation (chalk, marlstone, shale), from the Late Cretaceous, 66 to 100 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 43×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Chalk, marlstone, shale. Age: Late Cretaceous, 66 to 100 million years old. About 16 mi of the line.
Shale, bentonite. Age: Late Cretaceous, 66 to 100 million years old. About 3 mi of the line.
Shale. Age: Late Cretaceous, 66 to 100 million years old. About 2 mi of the line.
Sandstone. Age: Early Cretaceous to Late Cretaceous, 66 to 145 million years old. About 2 mi of the line.
Shale, mudstone, marlstone. Age: Late Cretaceous, 66 to 100 million years old. About 1 mi of the line.
Shale. Age: Late Cretaceous, 66 to 100 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 Irene reaches the Gulf of America by way of Frog Creek, the Vermillion, the Missouri and the Mississippi: about 1,980 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 Irene; river miles along the main stem, rounded.
Irene has a hot-summer humid continental climate. Summer afternoons average 84° in July; winter nights fall to about 7° in January. A normal year brings about 30 inches of snow; with the rain, that comes to about 27 inches of water.
On November 14 Irene normally reaches 46° and falls to 23°. The record high is 76°, in 1999; the record low −19°, in 1959. The most rain on this date, 1.54 in, fell in 1926.
Normals 1991–2020 and records since 1897 at Centerville 6 SE, 13 miles east-southeast, 120 ft lower. NOAA, through RCC-ACIS.