The South Branch 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 cloudy
Mostly cloudy; warmer
Mostly sunny
Mostly sunny
Partly cloudy
Partly cloudy
Partly cloudy
−4° on Nov. 15, 2019, the coldest reading for this week of the year since 1891. Next is −3° in 1943.
South Branch’s center stands about 1,200 ft above sea level. Within three miles the land runs from 1,100 ft to 1,360 ft, a difference of 260 ft: rolling country. The highest named summit within 15 miles is Bald Hill, about 1,420 ft, 10 miles north.
Under the town center the state geologic map shows Michigan Formation (shale), from the Carboniferous, 324 to 359 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 58×. 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 10 mi of the line.
Sandstone. Age: Carboniferous, 324 to 359 million years old. About 8 mi of the line.
Shale. Age: Carboniferous, 324 to 359 million years old. About 6 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 South Branch reaches Lake Huron by way of the South Branch Au Sable and the Au Sable: about 110 river miles. From there it moves on through the Great Lakes, over Niagara Falls and down the St. Lawrence to the Atlantic.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of South Branch; river miles along the main stem, rounded.
South Branch has a warm-summer humid continental climate. Summer afternoons average 80° in July; winter nights fall to about 9° in February. A normal year brings about 88 inches of snow; with the rain, that comes to about 33 inches of water.
On November 14 South Branch normally reaches 43° and falls to 27°. The record high is 65°, in 1953; the record low 3°, in 1940. The most rain on this date, 0.76 in, fell in 1951.
Normals 1991–2020 and records since 1891 at Grayling, 13 miles west-northwest. NOAA, through RCC-ACIS.
