The Ashton 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.
76° on Nov. 14, 1999, the hottest reading for this week of the year since 1893. Next is 74° in 1912.
Ashton’s center stands about 1,450 ft above sea level. Within three miles the land runs from 1,420 ft to 1,550 ft, a difference of 130 ft: gently rolling country. The highest named summit within 15 miles is Hawkeye Point, about 1,660 ft, 11 miles north-northeast.
Under the town center the state geologic map shows Dakata and Windrow Formations (sandstone, shale), from the Early Cretaceous to Late Cretaceous, 94 to 113 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 64×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Sandstone, shale. Age: Early Cretaceous to Late Cretaceous, 94 to 113 million years old. About 17 mi of the line.
Shale. Age: Late Cretaceous, 90 to 100 million years old. About 8 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 Ashton reaches the Gulf of America by way of Otter Creek, the Little Rock, the Rock River, the Big Sioux, the Missouri and the Mississippi: about 2,040 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 Ashton; river miles along the main stem, rounded.
Ashton has a warm-summer humid continental climate. Summer afternoons average 82° in July; winter nights fall to about 5° in January. A normal year brings about 42 inches of snow; with the rain, that comes to about 30 inches of water.
On November 14 Ashton normally reaches 43° and falls to 23°. The record high is 76°, in 1999; the record low −20°, in 1959. The most rain on this date, 1.62 in, fell in 1909.
Normals 1991–2020 and records since 1893 at Sibley, 7 miles north-northeast. NOAA, through RCC-ACIS.