The Marion 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.
71° on Nov. 16, 1953, the hottest reading for this week of the year since 1886. Next is 71° in 1999.
Marion’s center stands about 1,150 ft above sea level. Within three miles the land runs from 1,060 ft to 1,290 ft, a difference of 230 ft: rolling country. The highest named summit within 15 miles is Chance Hollow Hill, about 1,320 ft, 4 miles southeast.
Under the town center the state geologic map shows Middle and Upper Ordovician (shale, limestone, sandstone), from the Middle Ordovician to Late Ordovician, 445 to 471 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 57×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Limestone, dolostone. Age: Late Ordovician, 445 to 459 million years old. About 13 mi of the line.
Shale, limestone, sandstone. Age: Middle Ordovician to Late Ordovician, 445 to 471 million years old. About 9 mi of the line.
Dolostone, sandstone. Age: Early Ordovician, 471 to 487 million years old. About 2 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 Marion reaches the Gulf of America by way of Badger Run, Bear Creek, the South Fork Zumbro, the Zumbro and the Mississippi: about 1,820 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Marion; river miles along the main stem, rounded.
Marion has a warm-summer humid continental climate. Summer afternoons average 80° in July; winter nights fall to about 7° in January. A normal year brings about 53 inches of snow; with the rain, that comes to about 35 inches of water.
On November 14 Marion normally reaches 42° and falls to 26°. The record high is 69°, in 2025; the record low −5°, in 1916. The most rain on this date, 0.88 in, fell in 1973.
Normals 1991–2020 and records since 1886 from the Rochester Area threaded record (Rochester International Airport, 7 miles west-southwest, 160 ft higher). NOAA, through RCC-ACIS.