The Hillsboro 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 cloudy
Partly cloudy
Mostly sunny
Mostly sunny
Mostly sunny
Partly cloudy
Showers likely
81° on Nov. 14, 1999, the hottest reading for this week of the year since 1966. Next is 77° in 1989.
Hillsboro’s center stands about 1,440 ft above sea level. Within three miles the land runs from 1,350 ft to 1,490 ft, a difference of 140 ft: gently rolling country.
Under the town center the state geologic map shows Sumner Group (shale), from the Permian, 252 to 299 million years old.
The section below crosses 5 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.
Shale. Age: Permian, 252 to 299 million years old. About 12 mi of the line.
Arkose. Age: Miocene, 5.3 to 23 million years old. About 4 mi of the line.
Shale, limestone. Age: Permian, 252 to 299 million years old. About 4 mi of the line.
Sandstone, black-shale. Age: Early Cretaceous, 100 to 145 million years old. About 3 mi of the line.
Sand, silt, clay. Age: Pleistocene to Holocene, less than 2.6 million years old. About 2 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 Hillsboro reaches the Gulf of America by way of the South Cottonwood, the Cottonwood, the Neosho, the Arkansas and the Mississippi: about 1,500 river miles.
Lakes on the way: Murray Lake and Ozark Lake.
600 miles of the trip are on the Mississippi.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Hillsboro; river miles along the main stem, rounded.
Hillsboro has a hot-summer humid continental climate. Summer afternoons average 92° in July; winter nights fall to about 21° in January. About 34 inches of rain fall in a normal year.
On November 14 Hillsboro normally reaches 56° and falls to 35°. The record high is 81°, in 1999; the record low 8°, in 1986. The most rain on this date, 0.30 in, fell in 1993.
Normals 1991–2020 and records since 1966 at Marion Reservoir, 7 miles east-northeast. NOAA, through RCC-ACIS.
