The Granite Ledge 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
Mostly sunny
Partly cloudy
Mostly cloudy
Partly cloudy
Showers likely
72° on Nov. 14, 1999, the hottest reading for this week of the year since 1897. Next is 69° in 1953.
Granite Ledge’s center stands about 1,170 ft above sea level. Within three miles the land runs from 1,110 ft to 1,250 ft, a difference of 140 ft: gently rolling country.
Under the town center the state geologic map shows Granitoid intrusions, variably magnetic (granitic), from the Paleoproterozoic, 1.6 to 1.8 billion 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 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.
Age: Paleoproterozoic, 1.6 to 1.8 billion years old. About 11 mi of the line.
Granitic. Age: Paleoproterozoic, 1.6 to 1.8 billion years old. About 9 mi of the line.
Mylonite, gneiss, schist. Age: Paleoproterozoic, 1.6 to 2.5 billion years old. About 3 mi of the line.
Tonalite, diorite. Age: Paleoproterozoic, 1.6 to 1.8 billion years old. About 1 mi of the line.
Age: Paleoproterozoic, 1.8 to 2 billion years old. About 0.3 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 Granite Ledge reaches the Gulf of America by way of the West Branch Rum, the Rum and the Mississippi: about 1,970 river miles.
Lake on the way: Lake Pepin.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Granite Ledge; river miles along the main stem, rounded.
Granite Ledge has a warm-summer humid continental climate. Summer afternoons average 80° in July; winter nights fall to about 1° in January. A normal year brings about 49 inches of snow; with the rain, that comes to about 31 inches of water.
On November 14 Granite Ledge normally reaches 40° and falls to 22°. The record high is 72°, in 1999; the record low −6°, in 1919. The most rain on this date, 1.11 in, fell in 1909.
Normals 1991–2020 and records since 1897 at Milaca, 7 miles east, 110 ft lower. NOAA, through RCC-ACIS.
