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.
Sunny
Mostly sunny; warmer
Mostly sunny
Mostly sunny
Partly cloudy
Mostly sunny
Chance of showers
75° on Nov. 14, 1999, the hottest reading for this week of the year since 1956. Next is 70° in 1990.
Marietta’s center stands about 860 ft above sea level. Within three miles the land runs from 630 ft to 1,150 ft, a difference of 520 ft: hilly country. The highest named summit within 15 miles is Pine Knob, about 1,090 ft, 7 miles south-southeast.
Under the town center the state geologic map shows Prairie du Chien Group (dolostone), from the Early Ordovician, 471 to 487 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 33×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Dolostone. Age: Early Ordovician, 471 to 487 million years old. About 13 mi of the line.
Sandstone. Age: Ordovician, 445 to 487 million years old. About 5 mi of the line.
Sandstone. Age: Cambrian, 487 to 542 million years old. About 5 mi of the line.
Dolostone. Age: Ordovician, 445 to 487 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 Clear Creek, the Wisconsin and the Mississippi: about 1,640 river miles.
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 7° in January. A normal year brings about 38 inches of snow; with the rain, that comes to about 38 inches of water.
On November 14 Marietta normally reaches 46° and falls to 27°. The record high is 75°, in 1999; the record low 6°, in 1996. The most rain on this date, 0.57 in, fell in 1994.
Normals 1991–2020 and records since 1956 at Gays Mills, 12 miles north-northwest, 170 ft lower. NOAA, through RCC-ACIS.
