The Mount Ayr 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
Partly cloudy; warmer
Mostly sunny
Mostly sunny
Partly cloudy
Partly cloudy
Chance of showers
79° on Nov. 14, 1999, the hottest reading for this week of the year since 1893. Next is 78° in 1941.
Mount Ayr’s center stands about 1,230 ft above sea level. Within three miles the land runs from 1,070 ft to 1,230 ft, a difference of 160 ft: gently rolling country.
Under the town center the state geologic map shows Kansas City Group (limestone, shale), from the Late Pennsylvanian, 299 to 307 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.
Limestone, shale. Age: Late Pennsylvanian, 299 to 307 million years old. About 16 mi of the line.
Limestone, shale. Age: Late Pennsylvanian, 299 to 307 million years old. About 5 mi of the line.
Shale, limestone. Age: Carboniferous, 299 to 324 million years old. About 2 mi of the line.
Shale, mudstone. Age: Late Pennsylvanian, 299 to 307 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 Mount Ayr reaches the Gulf of America by way of the Middle Fork Grand, the Grand River, the Missouri and the Mississippi: about 1,600 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 Mount Ayr; river miles along the main stem, rounded.
Mount Ayr has a hot-summer humid continental climate. Summer afternoons average 85° in July; winter nights fall to about 12° in January. A normal year brings about 20 inches of snow; with the rain, that comes to about 37 inches of water.
On November 14 Mount Ayr normally reaches 50° and falls to 28°. The record high is 79°, in 1999; the record low 0°, in 1940. The most rain on this date, 1.30 in, fell in 1931.
Normals 1991–2020 and records since 1893 at Mount Ayr, here. NOAA, through RCC-ACIS.
