The Pomeroy 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
Partly cloudy; warmer
Mostly sunny
Partly cloudy
Partly cloudy
Mostly sunny
Showers likely
78° on Nov. 15, 1999, the hottest reading for this week of the year since 1894. Next is 76° in 2012.
Pomeroy’s center stands about 1,230 ft above sea level. Within three miles the land runs from 1,210 ft to 1,260 ft, a difference of 50 ft: nearly flat ground.
Under the town center the state geologic map shows Manson Group, Crater Moat area; Manson Impact Structure (sedimentary-breccia, shale), from the Late Cretaceous, 72 to 84 million years old.
The section below crosses 5 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 64×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Sedimentary-breccia, shale. Age: Late Cretaceous, 72 to 84 million years old. About 11 mi of the line.
Sedimentary-breccia, shale. Age: Late Cretaceous, 72 to 84 million years old. About 7 mi of the line.
Shale, sandstone, siltstone. Age: Early Pennsylvanian to Middle Pennsylvanian, 307 to 324 million years old. About 3 mi of the line.
Sandstone, shale. Age: Early Cretaceous to Late Cretaceous, 94 to 113 million years old. About 2 mi of the line.
Dolostone, limestone. Age: Early Mississippian to Middle Mississippian, 331 to 359 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 Pomeroy reaches the Gulf of America by way of Lake Creek, the North Raccoon, the Des Moines and the Mississippi: about 1,710 river miles.
Lake on the way: Roberts Creek.
1,330 miles of the trip are on the Mississippi.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Pomeroy; river miles along the main stem, rounded.
Pomeroy has a hot-summer humid continental climate. Summer afternoons average 83° in July; winter nights fall to about 9° in January. A normal year brings about 32 inches of snow; with the rain, that comes to about 34 inches of water.
On November 14 Pomeroy normally reaches 46° and falls to 26°. The record high is 72°, in 1964; the record low −9°, in 1959. The most rain on this date, 1.90 in, fell in 1926.
Normals 1991–2020 and records since 1894 at Rockwell City, 11 miles south-southeast. NOAA, through RCC-ACIS.
