The St. Charles 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
Mostly sunny; warmer
Partly cloudy
Partly cloudy
Partly cloudy
Partly cloudy
Showers likely
71° on Nov. 16, 1953, the hottest reading for this week of the year since 1886. Next is 71° in 1999.
St. Charles’s center stands about 1,170 ft above sea level. Within three miles the land runs from 1,070 ft to 1,330 ft, a difference of 260 ft: rolling country.
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 32×. 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, sandstone. Age: Early Ordovician, 471 to 487 million years old. About 12 mi of the line.
Shale, limestone, sandstone. Age: Middle Ordovician to Late Ordovician, 445 to 471 million years old. About 7 mi of the line.
Sandstone, siltstone, shale. Age: Cambrian, 487 to 497 million years old. About 3 mi of the line.
Limestone, dolostone. Age: Late Ordovician, 445 to 459 million years old. About 1 mi of the line.
Sandstone, siltstone, shale. Age: Middle Cambrian to Cambrian, 487 to 521 million years old. About 0.5 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 St. Charles reaches the Gulf of America by way of the South Fork Whitewater, the Whitewater and the Mississippi: about 1,750 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of St. Charles; river miles along the main stem, rounded.
St. Charles has a warm-summer humid continental climate. Summer afternoons average 80° in July; winter nights fall to about 7° in January. A normal year brings about 53 inches of snow; with the rain, that comes to about 35 inches of water.
On November 14 St. Charles normally reaches 42° and falls to 26°. The record high is 69°, in 2025; the record low −5°, in 1916. The most rain on this date, 0.88 in, fell in 1973.
Normals 1991–2020 and records since 1886 from the Rochester Area threaded record (Rochester International Airport, 24 miles west-southwest, 140 ft higher). NOAA, through RCC-ACIS.
