The Riverdale 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
Mostly sunny
Sunny
Partly cloudy
Partly cloudy
Partly cloudy
75° on Nov. 11, 2020, the hottest reading for this week of the year since 1887. Next is 70° in 1909.
Riverdale’s center stands about 800 ft above sea level. Within three miles the land runs from 780 ft to 930 ft, a difference of 150 ft: gently rolling country.
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 2 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 54×. 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 15 mi of the line.
Shale. Age: Jurassic, 145 to 202 million years old. About 9 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 Riverdale reaches Lake Huron by way of the Pine River, the Chippewa, the Tittabawassee and the Saginaw: about 110 river miles. From there it moves on through the Great Lakes, over Niagara Falls and down the St. Lawrence to the Atlantic.
65 miles of the trip are on the Pine River.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Riverdale; river miles along the main stem, rounded.
Riverdale has a warm-summer humid continental climate. Summer afternoons average 82° in July; winter nights fall to about 15° in January. A normal year brings about 39 inches of snow; with the rain, that comes to about 34 inches of water.
On November 14 Riverdale normally reaches 46° and falls to 30°. The record high is 67°, in 1989; the record low 9°, in 1986. The most rain on this date, 1.25 in, fell in 1927.
Normals 1991–2020 and records since 1887 at Alma, 10 miles east. NOAA, through RCC-ACIS.
