The Duncan 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
Mostly sunny
Partly cloudy
Partly cloudy
Partly cloudy
Showers likely
78° on Nov. 13, 1999, the hottest reading for this week of the year since 1893. Next is 78° in 2025.
Duncan’s center stands about 1,500 ft above sea level. Within three miles the land runs from 1,460 ft to 1,560 ft, a difference of 100 ft: gently rolling country.
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.
Shale. Age: Late Cretaceous, 66 to 100 million years old. About 16 mi of the line.
Limestone, shale. Age: Late Cretaceous, 66 to 100 million years old. About 9 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 Duncan reaches the Gulf of America by way of the Platte, the Missouri and the Mississippi: about 1,870 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 Duncan; river miles along the main stem, rounded.
Duncan has a hot-summer humid continental climate. Summer afternoons average 87° in July; winter nights fall to about 14° in January. A normal year brings about 26 inches of snow; with the rain, that comes to about 29 inches of water.
On November 14 Duncan normally reaches 48° and falls to 28°. The record high is 78°, in 2025; the record low −7°, in 1940. The most rain on this date, 1.16 in, fell in 1926.
Normals 1991–2020 and records since 1893 at Columbus 3 NE, 10 miles east-northeast. NOAA, through RCC-ACIS.
