The Mahaska 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
Mostly sunny
Partly cloudy
Mostly sunny
Partly cloudy
Showers likely
−7° on Nov. 12, 2019, the coldest reading for this week of the year since 1893. Next is 0° in 1916.
Mahaska’s center stands about 1,610 ft above sea level. Within three miles the land runs from 1,480 ft to 1,610 ft, a difference of 130 ft: gently rolling country.
Under the town center the state geologic map shows Loess (silt), from the Pleistocene to Holocene, less than 2.6 million years old.
The section below crosses 3 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.
Silt. Age: Pleistocene to Holocene, less than 2.6 million years old. About 15 mi of the line.
Sandstone, shale. Age: Early Cretaceous, 100 to 145 million years old. About 7 mi of the line.
Shale, limestone. Age: Late Cretaceous, 66 to 100 million years old. About 3 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 Mahaska reaches the Gulf of America by way of Myer Creek, Mill Creek, the Little Blue, the Big Blue, the Kansas, the Missouri and the Mississippi: about 1,850 river miles.
Lake on the way: Tuttle Creek 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 Mahaska; river miles along the main stem, rounded.
Mahaska has a hot-summer humid continental climate. Summer afternoons average 88° in July; winter nights fall to about 14° in January. A normal year brings about 21 inches of snow; with the rain, that comes to about 32 inches of water.
On November 14 Mahaska normally reaches 53° and falls to 28°. The record high is 83°, in 1999; the record low 0°, in 1986. The most rain on this date, 1.22 in, fell in 1926.
Normals 1991–2020 and records since 1893 at Fairbury 7 S, 10 miles east-northeast, 150 ft lower. NOAA, through RCC-ACIS.
