The Grand Rivers 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.
Sunny
Mostly sunny; warmer
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Mostly sunny
3.50 inches of rain fell in two days, the most for this week of the year since records began in 1980. The next wettest, 3.44 inches, fell in 2011.
Grand Rivers’s center stands about 420 ft above sea level. Within three miles the land runs from 180 ft to 500 ft, a difference of 320 ft: rolling country. The highest named summit within 15 miles is Bald Knob, about 620 ft, 12 miles north-northwest.
Under the town center the state geologic map shows Continental deposits, undifferentiated (gravel, sand), from the Tertiary to Holocene, less than 66 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 35×. 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: Cretaceous to Tertiary, 2.6 to 145 million years old. About 5 mi of the line.
Conglomerate. Age: Late Cretaceous, 66 to 100 million years old. About 5 mi of the line.
Gravel, sand. Age: Tertiary to Holocene, less than 66 million years old. About 2 mi of the line.
Limestone. Age: Carboniferous, 324 to 359 million years old. About 1 mi of the line.
Dolostone, limestone. Age: Carboniferous, 324 to 359 million years old. About 0.8 mi of the line.
Limestone. Age: Carboniferous, 324 to 359 million years old. About 0.4 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 Grand Rivers reaches the Gulf of America by way of Bards Lake, the Cumberland, the Ohio and the Mississippi: about 1,060 river miles.
Lake on the way: Bards Lake.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Grand Rivers; river miles along the main stem, rounded.
Grand Rivers has a humid subtropical climate. Summer afternoons average 88° in July; winter nights fall to about 26° in January. About 49 inches of rain fall in a normal year, with about 4 inches of snow.
On November 14 Grand Rivers normally reaches 58° and falls to 37°. The record high is 77°, in 1999; the record low 13°, in 1986. The most rain on this date, 1.47 in, fell in 2024.
Normals 1991–2020 and records since 1980 at Smithland Lock & Dam, 16 miles northwest. NOAA, through RCC-ACIS.
