The Primghar 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
Mostly sunny
Partly cloudy
Partly cloudy
Partly cloudy
Showers likely
−13° on Nov. 14, 1959, the coldest reading for this week of the year since 1895. Next is −12° in 1986.
Primghar’s center stands about 1,500 ft above sea level. Within three miles the land runs from 1,410 ft to 1,550 ft, a difference of 140 ft: gently rolling country.
Under the town center the state geologic map shows Dakata and Windrow Formations (sandstone, shale), from the Early Cretaceous to Late Cretaceous, 94 to 113 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.
Sandstone, shale. Age: Early Cretaceous to Late Cretaceous, 94 to 113 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.
A raindrop that lands in Primghar reaches the Gulf of America by way of Dry Run, Mill Creek, the Little Sioux, the Missouri and the Mississippi: about 1,980 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 Primghar; river miles along the main stem, rounded.
Primghar has a hot-summer humid continental climate. Summer afternoons average 85° in July; winter nights fall to about 9° in January. A normal year brings about 35 inches of snow; with the rain, that comes to about 31 inches of water.
On November 14 Primghar normally reaches 46° and falls to 27°. The record high is 74°, in 2025; the record low −13°, in 1959. The most rain on this date, 0.41 in, fell in 1997.
Normals 1991–2020 and records since 1895 at Primghar, here. NOAA, through RCC-ACIS.
