The Aurora 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
Mostly sunny
Partly cloudy
Partly cloudy
Partly cloudy; cooler
Showers likely
−17° on Nov. 14, 1959, the coldest reading for this week of the year since 1893. Next is −12° in 1997.
Aurora’s center stands about 1,630 ft above sea level. Within three miles the land runs from 1,590 ft to 1,670 ft, a difference of 80 ft: gently rolling country.
Under the town center the state geologic map shows Sioux Quartzite, from the Paleoproterozoic, 1.6 to 2.5 billion years old.
The section below crosses 3 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 47×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Quartzite. Age: Paleoproterozoic, 1.6 to 2.5 billion years old. About 18 mi of the line.
Shale, bentonite. Age: Late Cretaceous, 66 to 100 million years old. About 5 mi of the line.
Chalk, marlstone, shale. Age: Late Cretaceous, 66 to 100 million years old. About 0.7 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 Aurora reaches the Gulf of America by way of Medary Creek, the Big Sioux, the Missouri and the Mississippi: about 2,160 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 Aurora; river miles along the main stem, rounded.
Aurora has a warm-summer humid continental climate. Summer afternoons average 82° in July; winter nights fall to about 3° in January. A normal year brings about 36 inches of snow; with the rain, that comes to about 25 inches of water.
On November 14 Aurora normally reaches 42° and falls to 22°. The record high is 74°, in 1999; the record low −17°, in 1959. The most rain on this date, 0.39 in, fell in 1983.
Normals 1991–2020 and records since 1893 at Brookings 2 NE, 5 miles northwest. NOAA, through RCC-ACIS.
