The Mount Vernon 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.
Partly cloudy
Sunny; warmer
Mostly sunny
Partly cloudy
Partly cloudy
Partly cloudy; cooler
Showers likely
−22° on Nov. 14, 1959, the coldest reading for this week of the year since 1893. Next is −15° in 1940.
Mount Vernon’s center stands about 1,410 ft above sea level. Within three miles the land runs from 1,360 ft to 1,440 ft, a difference of 80 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 2 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 48×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Chalk, marlstone, shale. Age: Late Cretaceous, 66 to 100 million years old. About 13 mi of the line.
Shale, bentonite. Age: Late Cretaceous, 66 to 100 million years old. About 11 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 Mount Vernon reaches the Gulf of America by way of Dry Run, the James, the Missouri and the Mississippi: about 2,100 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 Mount Vernon; river miles along the main stem, rounded.
Mount Vernon has a hot-summer humid continental climate. Summer afternoons average 87° in July; winter nights fall to about 9° in January. About 21 inches of rain fall in a normal year.
On November 14 Mount Vernon normally reaches 46° and falls to 25°. The record high is 79°, in 2025; the record low −22°, in 1959. The most rain on this date, 0.46 in, fell in 1928.
Normals 1991–2020 and records since 1893 from the Mitchell Area threaded record (Mitchell Airport, 12 miles east-northeast, 110 ft lower). NOAA, through RCC-ACIS.
