The Gillett Grove 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; warmer
Mostly sunny
Partly cloudy
Partly cloudy
Mostly sunny
Showers likely
76° on Nov. 13, 1999, the hottest reading for this week of the year since 1895. Next is 74° in 2001.
Gillett Grove’s center stands about 1,340 ft above sea level. Within three miles the land runs from 1,280 ft to 1,430 ft, a difference of 150 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.
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 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 22 mi of the line.
Shale, limestone, dolostone. Age: Late Devonian, 374 to 384 million years old. About 2 mi of the line.
Shale, dolostone. Age: Late Ordovician, 447 to 454 million years old. About 0.8 mi of the line.
Dolostone, limestone. Age: Late Ordovician, 447 to 459 million years old. About 0.3 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 Gillett Grove reaches the Gulf of America by way of the Little Sioux, the Missouri and the Mississippi: about 1,990 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 Gillett Grove; river miles along the main stem, rounded.
Gillett Grove has a dry-winter hot-summer continental climate. Summer afternoons average 85° in July; winter nights fall to about 8° in January. About 27 inches of rain fall in a normal year.
On November 14 Gillett Grove normally reaches 45° and falls to 25°. The record high is 74°, in 2025; the record low −17°, in 1959. The most rain on this date, 0.91 in, fell in 1926.
Normals 1991–2020 and records since 1895 from the Spencer Area threaded record (Spencer Municipal Airport, 14 miles northwest). NOAA, through RCC-ACIS.
