The Afton 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
Partly cloudy
Partly cloudy
Partly cloudy
Partly cloudy
Showers likely
3.24 inches of rain fell in two days, the most for this week of the year since records began in 1918. The next wettest, 2.10 inches, fell in 1940.
Afton’s center stands about 730 ft above sea level. Within three miles the land runs from 670 ft to 1,020 ft, a difference of 350 ft: rolling country. The highest named summit within 15 miles is Big Mound, about 1,130 ft, 13 miles northeast.
The section below crosses 6 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 41×. 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, limestone, sandstone. Age: Middle Ordovician to Late Ordovician, 445 to 471 million years old. About 10 mi of the line.
Dolostone. Age: Early Ordovician, 471 to 487 million years old. About 8 mi of the line.
Sandstone. Age: Ordovician, 445 to 487 million years old. About 4 mi of the line.
Sandstone, siltstone, shale. Age: Cambrian, 487 to 497 million years old. About 2 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.
Dolostone, sandstone. Age: Early Ordovician, 471 to 487 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 Afton reaches the Gulf of America by way of Valley Branch and the Mississippi: about 1,810 river miles.
Lakes on the way: Lake Pepin and Lake Mallalieu 175.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Afton; river miles along the main stem, rounded.
Afton has a warm-summer humid continental climate. Summer afternoons average 82° in July; winter nights fall to about 4° in January. About 34 inches of rain fall in a normal year.
On November 14 Afton normally reaches 42° and falls to 24°. The record high is 71°, in 1990; the record low −8°, in 1940. The most rain on this date, 1.09 in, fell in 1951.
Normals 1991–2020 and records since 1918 at River Falls, 9 miles east-southeast, 210 ft higher. NOAA, through RCC-ACIS.
