The Interior 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.
Partly cloudy
Sunny; warmer
Mostly sunny
Partly cloudy
Partly cloudy; cooler
Partly cloudy
Chance of showers
78° on Nov. 12, 1999, the hottest reading for this week of the year since 1949. Next is 77° in 1990.
Interior’s center stands about 2,380 ft above sea level. Within three miles the land runs from 2,310 ft to 2,650 ft, a difference of 340 ft: rolling country. The highest named summit within 15 miles is The Castle, about 2,690 ft, 4 miles north-northwest.
Under the town center the state geologic map shows White River Group (claystone, siltstone, sandstone), from the Eocene to Oligocene, 23 to 56 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 28×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Claystone, siltstone, sandstone. Age: Eocene to Oligocene, 23 to 56 million years old. About 13 mi of the line.
Siltstone, sandstone. Age: Oligocene to Miocene, 5.3 to 34 million years old. About 4 mi of the line.
Shale, bentonite. Age: Late Cretaceous, 66 to 100 million years old. About 2 mi of the line.
Coarse-detrital, clay. Age: Quaternary, less than 2.6 million years old. About 2 mi of the line.
Coarse-detrital, fine-detrital. Age: Quaternary, less than 2.6 million years old. About 2 mi of the line.
Silt, sand. Age: Quaternary, less than 2.6 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 Interior reaches the Gulf of America by way of the White River, the Missouri and the Mississippi: about 2,390 river miles.
Lakes on the way: Lake Francis Case and Lewis and Clark 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 Interior; river miles along the main stem, rounded.
Interior has a hot-summer humid continental climate. Summer afternoons average 91° in July; winter nights fall to about 14° in January. A normal year brings about 38 inches of snow; with the rain, that comes to about 20 inches of water.
On November 14 Interior normally reaches 51° and falls to 26°. The record high is 76°, in 1990; the record low −21°, in 1959. The most rain on this date, 0.39 in, fell in 1956.
Normals 1991–2020 and records since 1949 at Interior 3 NE, 3 miles northeast. NOAA, through RCC-ACIS.
