The Grattan 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.
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9° on Nov. 17, 1959, the coldest reading for this week of the year since 1892. Next is 10° in 1933.
Grattan’s center stands about 840 ft above sea level. Within three miles the land runs from 810 ft to 960 ft, a difference of 150 ft: gently rolling country. The highest named summit within 15 miles is Cheney Hills, about 1,070 ft, 13 miles north-northwest.
Under the town center the state geologic map shows Saginaw Formation (sandstone, shale), from the Carboniferous, 299 to 324 million years old.
The section below crosses 3 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 45×. 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, shale. Age: Carboniferous, 299 to 324 million years old. About 14 mi of the line.
Shale. Age: Jurassic, 145 to 202 million years old. About 8 mi of the line.
Limestone. Age: Carboniferous, 324 to 359 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 Grattan reaches Lake Michigan by way of Seely Creek, the Flat and the Grand River: about 95 river miles. From there it moves on through the Great Lakes, over Niagara Falls and down the St. Lawrence to the Atlantic.
70 miles of the trip are on the Grand River.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Grattan; river miles along the main stem, rounded.
Grattan has a hot-summer humid continental climate. Summer afternoons average 83° in July; winter nights fall to about 19° in January. A normal year brings about 78 inches of snow; with the rain, that comes to about 39 inches of water.
On November 14 Grattan normally reaches 48° and falls to 33°. The record high is 68°, in 1902; the record low 13°, in 1969. The most rain on this date, 1.41 in, fell in 1957.
Normals 1991–2020 and records since 1892 from the Grand Rapids Area threaded record (Grand Rapids Gerald R Ford International Airport, 16 miles south-southwest). NOAA, through RCC-ACIS.
