The Fort Thompson 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
Sunny; warmer
Mostly sunny
Partly cloudy
Partly cloudy
Partly cloudy
Chance of showers
77° on Nov. 16, 1999, the hottest reading for this week of the year since 1965. Next is 74° in 1990.
Fort Thompson’s center stands about 1,440 ft above sea level. Within three miles the land runs from 1,360 ft to 1,680 ft, a difference of 320 ft: rolling country. The highest named summit within 15 miles is Medicine Butte, about 2,210 ft, 11 miles southwest.
The section below crosses 4 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 31×. 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, bentonite. Age: Late Cretaceous, 66 to 100 million years old. About 16 mi of the line.
Silt, sand. Age: Quaternary, less than 2.6 million years old. About 4 mi of the line.
Sandstone, limestone, siltstone. Age: Miocene to Pliocene, 2.6 to 23 million years old. About 0.9 mi of the line.
Chalk, marlstone, shale. Age: Late Cretaceous, 66 to 100 million years old. About 0.5 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 Fort Thompson reaches the Gulf of America by way of the Missouri and the Mississippi: about 2,140 river miles.
Lakes on the way: 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 Fort Thompson; river miles along the main stem, rounded.
Fort Thompson has a dry-winter hot-summer continental climate. Summer afternoons average 87° in July; winter nights fall to about 7° in January. A normal year brings about 19 inches of snow; with the rain, that comes to about 20 inches of water.
On November 14 Fort Thompson normally reaches 47° and falls to 24°. The record high is 73°, in 2016; the record low −3°, in 2014. The most rain on this date, 0.38 in, fell in 1988.
Normals 1991–2020 and records since 1965 at Lake Sharpe Project, here. NOAA, through RCC-ACIS.
