The Irena 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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Showers likely
79° on Nov. 14, 1999, the hottest reading for this week of the year since 1893. Next is 78° in 1941.
Irena’s center stands about 1,150 ft above sea level. Within three miles the land runs from 960 ft to 1,170 ft, a difference of 210 ft: rolling country.
Under the town center the state geologic map shows Lansing Group (shale, limestone), from the Carboniferous, 299 to 324 million years old.
The section below crosses 4 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 58×. 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, mudstone. Age: Late Pennsylvanian, 299 to 307 million years old. About 9 mi of the line.
Shale, limestone. Age: Carboniferous, 299 to 324 million years old. About 8 mi of the line.
Limestone, shale. Age: Carboniferous, 299 to 324 million years old. About 6 mi of the line.
Limestone, shale. Age: Late Pennsylvanian, 299 to 307 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.
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 Irena reaches the Gulf of America by way of Joes Branch, the Middle Fork Grand, the Grand River, the Missouri and the Mississippi: about 1,580 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 Irena; river miles along the main stem, rounded.
Irena has a hot-summer humid continental climate. Summer afternoons average 85° in July; winter nights fall to about 12° in January. A normal year brings about 20 inches of snow; with the rain, that comes to about 37 inches of water.
On November 14 Irena normally reaches 50° and falls to 28°. The record high is 79°, in 1999; the record low 0°, in 1940. The most rain on this date, 1.30 in, fell in 1931.
Normals 1991–2020 and records since 1893 at Mount Ayr, 13 miles northeast. NOAA, through RCC-ACIS.
