The Posen 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 sunny
Mostly sunny; warmer
Mostly sunny
Partly cloudy
Mostly cloudy
Partly cloudy
Showers likely
77° on Nov. 13, 1999, the hottest reading for this week of the year since 1935. Next is 75° in 1939.
Posen’s center stands about 1,070 ft above sea level. Within three miles the land runs from 1,040 ft to 1,090 ft, a difference of 50 ft: nearly flat ground.
Under the town center the state geologic map shows Granitic orthogneiss and migmatite (orthogneiss, migmatite), from the Paleoarchean to Mesoarchean, 2.8 to 3.6 billion 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 64×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Conglomerate, sandstone, mudstone. Age: Late Cretaceous, 72 to 100 million years old. About 9 mi of the line.
Orthogneiss, migmatite. Age: Paleoarchean to Mesoarchean, 2.8 to 3.6 billion years old. About 7 mi of the line.
Granitic. Age: Neoarchean, 2.5 to 2.8 billion years old. About 4 mi of the line.
Mafic-volcanic, hypabyssal. Age: Archean to Paleoproterozoic. About 2 mi of the line.
Orthogneiss. Age: Paleoarchean to Mesoarchean, 2.8 to 3.6 billion years old. About 2 mi of the line.
Leucocratic-granitic. Age: Neoarchean, 2.5 to 2.8 billion years old. About 0.5 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 Posen reaches the Gulf of America by way of Boiling Spring Creek, the Minnesota and the Mississippi: about 2,060 river miles.
Lake on the way: Lake Pepin.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Posen; river miles along the main stem, rounded.
Posen has a hot-summer humid continental climate. Summer afternoons average 85° in July; winter nights fall to about 4° in January. A normal year brings about 44 inches of snow; with the rain, that comes to about 29 inches of water.
On November 14 Posen normally reaches 44° and falls to 23°. The record high is 70°, in 1953; the record low −8°, in 1940. The most rain on this date, 0.33 in, fell in 1983.
Normals 1991–2020 and records since 1935 at Marshall, 15 miles west-southwest. NOAA, through RCC-ACIS.
