The Napoleon 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
Mostly cloudy; cooler
Partly cloudy
Chance of showers
−20° on Nov. 13, 1940, the coldest reading for this week of the year since 1893. Next is −20° in 1955.
Napoleon’s center stands about 1,960 ft above sea level. Within three miles the land runs from 1,930 ft to 2,070 ft, a difference of 140 ft: gently rolling country.
Under the town center the state geologic map shows Hell Creek Formation (sandstone, siltstone, claystone), from the Late Cretaceous, 66 to 100 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.
Shale, sandstone. Age: Late Cretaceous, 66 to 100 million years old. About 15 mi of the line.
Sandstone, siltstone, claystone. 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 Napoleon reaches the Gulf of America by way of Goose Creek, Long Lake Creek, Random Creek, Apple Creek, the Missouri and the Mississippi: about 2,590 river miles.
Lakes on the way: Lake Oahe, Lake Sharpe, Lake Francis Case and Lewis and Clark Lake.
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 Napoleon; river miles along the main stem, rounded.
Napoleon has a warm-summer humid continental climate. Summer afternoons average 82° in July; winter nights fall to about 1° in January. A normal year brings about 53 inches of snow; with the rain, that comes to about 21 inches of water.
On November 14 Napoleon normally reaches 39° and falls to 19°. The record high is 71°, in 1939; the record low −20°, in 1940. The most rain on this date, 0.82 in, fell in 1944.
Normals 1991–2020 and records since 1893 at Napoleon, here. NOAA, through RCC-ACIS.
