The Mahnomen 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
Partly cloudy
Mostly cloudy
Chance of showers
Mostly cloudy; cooler
Showers likely
65° on Nov. 14, 2025, the hottest reading for this week of the year since 1924. Next is 61° in 1981.
Mahnomen’s center stands about 1,210 ft above sea level. Within three miles the land runs from 1,180 ft to 1,240 ft, a difference of 60 ft: nearly flat ground.
Under the town center the state geologic map shows Mafic metavolcanic rocks (metabasalt, greenstone), from the Neoarchean, 2.5 to 2.8 billion years old.
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 49×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Granitic. Age: Neoarchean, 2.5 to 2.8 billion years old. About 9 mi of the line.
Metabasalt, greenstone. Age: Neoarchean, 2.5 to 2.8 billion years old. About 8 mi of the line.
Alkalic-volcanic. Age: Neoarchean, 2.5 to 2.8 billion years old. About 6 mi of the line.
Plutonic. Age: Archean. 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 Mahnomen reaches Hudson Bay by way of the Wild Rice, the Red River of the North and the Nelson: about 1,120 river miles. Past the border it runs north through Canada to Hudson Bay.
Lake on the way: Lake Winnipeg.
400 miles of the trip are on the Nelson.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Mahnomen; river miles along the main stem, rounded.
Mahnomen has a warm-summer humid continental climate. Summer afternoons average 78° in July; winter nights fall to about −2° in January. About 26 inches of rain fall in a normal year.
On November 14 Mahnomen normally reaches 34° and falls to 20°. The record high is 65°, in 2025; the record low −8°, in 1959. The most rain on this date, 0.50 in, fell in 1951.
Normals 1991–2020 and records since 1924 at Mahnomen, here. NOAA, through RCC-ACIS.
