The Lake Madison 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
Partly cloudy
Partly cloudy; cooler
Showers likely
75° on Nov. 14, 1999, the hottest reading for this week of the year since 1961. Next is 72° in 2001.
Lake Madison’s center stands about 1,620 ft above sea level. Within three miles the land runs from 1,590 ft to 1,750 ft, a difference of 160 ft: gently rolling country.
Under the town center the state geologic map shows Niobrara Formation (chalk, marlstone, shale), from the Late Cretaceous, 66 to 100 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 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.
Shale, bentonite. Age: Late Cretaceous, 66 to 100 million years old. About 13 mi of the line.
Chalk, marlstone, shale. Age: Late Cretaceous, 66 to 100 million years old. About 8 mi of the line.
Quartzite. Age: Paleoproterozoic, 1.6 to 2.5 billion years old. About 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 Lake Madison reaches the Gulf of America by way of Skunk Creek, the Big Sioux, the Missouri and the Mississippi: about 2,120 river miles.
1,170 miles of the trip are on the Mississippi.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Lake Madison; river miles along the main stem, rounded.
Lake Madison has a hot-summer humid continental climate. Summer afternoons average 83° in July; winter nights fall to about 5° in January. A normal year brings about 37 inches of snow; with the rain, that comes to about 26 inches of water.
On November 14 Lake Madison normally reaches 43° and falls to 23°. The record high is 75°, in 1999; the record low −6°, in 2014. The most rain on this date, 0.12 in, fell in 2024.
Normals 1991–2020 and records since 1961 at Madison 2 SE, 4 miles northwest. NOAA, through RCC-ACIS.
