The Macomb 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.
4° on Nov. 16, 1933, the coldest reading for this week of the year since 1896. Next is 10° in 1908.
Macomb’s center stands about 630 ft above sea level. Within three miles the land runs from 600 ft to 720 ft, a difference of 120 ft: gently rolling country. The highest named summit within 15 miles is Grampian Hills, about 1,270 ft, 15 miles west-northwest.
Under the town center the state geologic map shows Sunbury Shale (black-shale), from the Devonian to Carboniferous, 324 to 422 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 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.
Shale. Age: Carboniferous, 324 to 359 million years old. About 12 mi of the line.
Black-shale. Age: Late Devonian, 359 to 384 million years old. About 6 mi of the line.
Sandstone. Age: Late Devonian, 359 to 384 million years old. About 3 mi of the line.
Shale. Age: Late Devonian, 359 to 384 million years old. About 2 mi of the line.
Black-shale. Age: Devonian to Carboniferous, 324 to 422 million years old. About 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 Macomb reaches Lake St. Clair by way of the Miller Drain and the Clinton: about 17 river miles. From there it moves on through the Great Lakes, over Niagara Falls and down the St. Lawrence to the Atlantic.
Often dry. About 40% of the way is mapped as streams that run only after rain or snowmelt; the water makes the whole trip in floods.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Macomb; river miles along the main stem, rounded.
Macomb has a hot-summer humid continental climate. Summer afternoons average 82° in July; winter nights fall to about 18° in January. A normal year brings about 32 inches of snow; with the rain, that comes to about 35 inches of water.
On November 14 Macomb normally reaches 48° and falls to 33°. The record high is 70°, in 1909; the record low 11°, in 1933. The most rain on this date, 0.94 in, fell in 1957.
Normals 1991–2020 and records since 1896 at Mt. Clemens Ang Base, 10 miles southeast. NOAA, through RCC-ACIS.