The Grundy Center 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
Mostly sunny
Partly cloudy
Mostly sunny
Showers likely
80° on Nov. 14, 1999, the hottest reading for this week of the year since 1893. Next is 77° in 2012.
Grundy Center’s center stands about 1,020 ft above sea level. Within three miles the land runs from 960 ft to 1,070 ft, a difference of 110 ft: gently rolling country.
Under the town center the state geologic map shows Lime Creek Formation (shale, limestone, dolostone), from the Late Devonian, 374 to 384 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 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.
Shale, limestone, dolostone. Age: Late Devonian, 374 to 384 million years old. About 8 mi of the line.
Dolostone, limestone, siltstone. Age: Early Mississippian, 347 to 359 million years old. About 7 mi of the line.
Limestone, dolostone. Age: Middle Devonian to Late Devonian, 374 to 388 million years old. About 5 mi of the line.
Shale, siltstone. Age: Late Devonian, 359 to 374 million years old. About 4 mi of the line.
Shale, sandstone, siltstone. Age: Early Pennsylvanian to Middle Pennsylvanian, 307 to 324 million years old. About 0.4 mi of the line.
Limestone. Age: Early Mississippian to Middle Mississippian, 331 to 359 million years old. About 0.1 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 Grundy Center reaches the Gulf of America by way of Black Hawk Creek, the Cedar River, the Iowa and the Mississippi: about 1,640 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Grundy Center; river miles along the main stem, rounded.
Grundy Center 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 37 inches of water.
On November 14 Grundy Center normally reaches 46° and falls to 27°. The record high is 80°, in 1999; the record low −5°, in 1959. The most rain on this date, 1.30 in, fell in 1902.
Normals 1991–2020 and records since 1893 at Grundy Center, here. NOAA, through RCC-ACIS.
