The Ponca 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
78° on Nov. 13, 1999, the hottest reading for this week of the year since 1889. Next is 77° in 1971.
Ponca’s center stands about 1,180 ft above sea level. Within three miles the land runs from 1,080 ft to 1,350 ft, a difference of 270 ft: rolling country. The highest named summit within 15 miles is Cottonwood Hill, about 1,540 ft, 10 miles southwest.
Under the town center the state geologic map shows Greenhorn Limestone and Graneros Shale (shale, limestone), from the Late Cretaceous, 66 to 100 million years old.
The section below crosses 7 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 39×. 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. Age: Early Cretaceous to Late Cretaceous, 66 to 145 million years old. About 9 mi of the line.
Shale. Age: Late Cretaceous, 66 to 100 million years old. About 7 mi of the line.
Shale, limestone. Age: Late Cretaceous, 66 to 100 million years old. About 3 mi of the line.
Limestone, shale. Age: Late Cretaceous, 66 to 100 million years old. About 3 mi of the line.
Sandstone, shale. Age: Early Cretaceous, 100 to 145 million years old. About 1 mi of the line.
Shale. Age: Late Cretaceous, 90 to 100 million years old. About 0.9 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale. 1 smaller unit along the line are not listed.
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 Ponca reaches the Gulf of America by way of Aowa Creek, the Missouri and the Mississippi: about 1,910 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 Ponca; river miles along the main stem, rounded.
Ponca has a hot-summer humid continental climate. Summer afternoons average 85° in July; winter nights fall to about 10° in January. A normal year brings about 36 inches of snow; with the rain, that comes to about 29 inches of water.
On November 14 Ponca normally reaches 48° and falls to 26°. The record high is 76°, in 2025; the record low −9°, in 1959. The most rain on this date, 1.08 in, fell in 1926.
Normals 1991–2020 and records since 1889 from the Sioux City Area threaded record (Sioux City Airport, 21 miles southeast). NOAA, through RCC-ACIS.
