The Alsen 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.
68° on Nov. 14, 1939, the hottest reading for this week of the year since 1897. Next is 64° in 1953.
Alsen’s center stands about 1,580 ft above sea level. Within three miles the land runs from 1,560 ft to 1,600 ft, a difference of 40 ft: nearly flat ground.
Under the town center the state geologic map shows Pierre Formation (shale), from the Late Cretaceous, 66 to 100 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. Age: Late Cretaceous, 66 to 100 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.
Alsen has a dry-winter warm-summer continental climate. Summer afternoons average 77° in July; winter nights fall to about −5° in January. A normal year brings about 47 inches of snow; with the rain, that comes to about 21 inches of water.
On November 14 Alsen normally reaches 33° and falls to 16°. The record high is 68°, in 1939; the record low −20°, in 1919. The most rain on this date, 0.98 in, fell in 1944.
Normals 1991–2020 and records since 1897 at Langdon Experiment Farm, 19 miles east-northeast. NOAA, through RCC-ACIS.