The Altona 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.
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−5° on Nov. 17, 1959, the coldest reading for this week of the year since 1887. Next is 2° in 2019.
Altona’s center stands about 760 ft above sea level. Within three miles the land runs from 700 ft to 800 ft, a difference of 100 ft: gently rolling country.
Under the town center the state geologic map shows Carbondale Formation (shale, sandstone, coal), from the Middle Pennsylvanian to Late Pennsylvanian, 304 to 315 million years old.
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.
Shale, sandstone, coal. Age: Middle Pennsylvanian to Late Pennsylvanian, 304 to 315 million years old. About 24 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 Altona reaches the Gulf of America by way of Walnut Creek, Fox Creek, the Illinois and the Mississippi: about 1,450 river miles.
1,190 miles of the trip are on the Mississippi.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Altona; river miles along the main stem, rounded.
Altona has a hot-summer humid continental climate. Summer afternoons average 84° in July; winter nights fall to about 13° in January. About 39 inches of rain fall in a normal year.
On November 14 Altona normally reaches 49° and falls to 29°. The record high is 75°, in 1989; the record low 6°, in 1940. The most rain on this date, 2.08 in, fell in 1926.
Normals 1991–2020 and records since 1887 at Galva, 8 miles east-northeast. NOAA, through RCC-ACIS.
