The Greenfield 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.
79° on Nov. 13, 1999, the hottest reading for this week of the year since 1893. Next is 73° in 1917.
Greenfield’s center stands about 1,380 ft above sea level. Within three miles the land runs from 1,230 ft to 1,380 ft, a difference of 150 ft: gently rolling country.
Under the town center the state geologic map shows Dakata and Windrow Formations (sandstone, shale), from the Early Cretaceous to Late Cretaceous, 94 to 113 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 61×. 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 8 mi of the line.
Sandstone, shale. Age: Early Cretaceous to Late Cretaceous, 94 to 113 million years old. About 6 mi of the line.
Limestone, shale. Age: Middle Pennsylvanian to Late Pennsylvanian, 299 to 315 million years old. About 4 mi of the line.
Limestone, shale. Age: Late Pennsylvanian, 299 to 307 million years old. About 4 mi of the line.
Limestone, shale. Age: Late Pennsylvanian, 299 to 307 million years old. About 3 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 Greenfield reaches the Gulf of America by way of Marvel Creek, the Thompson, the Grand River, the Missouri and the Mississippi: about 1,660 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 Greenfield; river miles along the main stem, rounded.
Greenfield has a hot-summer humid continental climate. Summer afternoons average 84° in July; winter nights fall to about 11° in January. A normal year brings about 26 inches of snow; with the rain, that comes to about 36 inches of water.
On November 14 Greenfield normally reaches 48° and falls to 28°. The record high is 77°, in 1999; the record low −2°, in 1940. The most rain on this date, 0.73 in, fell in 2024.
Normals 1991–2020 and records since 1893 at Greenfield, here. NOAA, through RCC-ACIS.