The Marietta 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
−11° on Nov. 12, 1966, the coldest reading for this week of the year since 1940. Next is −7° in 2014.
Marietta’s center stands about 1,120 ft above sea level. Within three miles the land runs from 1,090 ft to 1,150 ft, a difference of 60 ft: nearly flat ground.
Under the town center the state geologic map shows Undifferentiated (conglomerate, sandstone, mudstone), from the Late Cretaceous, 72 to 100 million years old.
The section below crosses 4 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 31×. 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 14 mi of the line.
Shale. Age: Late Cretaceous, 66 to 100 million years old. About 6 mi of the line.
Shale, bentonite. Age: Late Cretaceous, 66 to 100 million years old. About 2 mi of the line.
Chalk, marlstone, shale. Age: Late Cretaceous, 66 to 100 million years old. About 1 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 Marietta reaches the Gulf of America by way of the West Branch Lac qui Parle, the Lac qui Parle, the Minnesota and the Mississippi: about 2,180 river miles.
Lake on the way: Lake Pepin.
1,750 miles of the trip are on the Mississippi.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Marietta; river miles along the main stem, rounded.
Marietta has a hot-summer humid continental climate. Summer afternoons average 83° in July; winter nights fall to about 3° in January. A normal year brings about 47 inches of snow; with the rain, that comes to about 26 inches of water.
On November 14 Marietta normally reaches 42° and falls to 23°. The record high is 75°, in 1990; the record low −7°, in 2014. The most rain on this date, 0.46 in, fell in 2024.
Normals 1991–2020 and records since 1940 at Madison Wwtp, 12 miles east. NOAA, through RCC-ACIS.
