The 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.
Sunny
Mostly sunny; warmer
Mostly sunny
Mostly cloudy
Chance of showers
Mostly cloudy; cooler
Chance of showers
66° on Nov. 14, 1999, the hottest reading for this week of the year since 1984. Next is 66° in 2025.
Ayr’s center stands about 1,200 ft above sea level. Within three miles the land runs from 1,140 ft to 1,230 ft, a difference of 90 ft: gently rolling country.
Under the town center the state geologic map shows Greenhorn Formation (shale), from the Late Cretaceous, 66 to 100 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.
Shale. Age: Late Cretaceous, 66 to 100 million years old. About 13 mi of the line.
Shale, sandstone. Age: Early Cretaceous to Late Cretaceous, 66 to 145 million years old. About 9 mi of the line.
Shale. Age: Late Cretaceous, 66 to 100 million years old. About 2 mi of the line.
Shale. Age: Late Cretaceous, 66 to 100 million years old. About 0.8 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 Ayr reaches Hudson Bay by way of Swan Creek, the Maple, the Sheyenne, the Red River of the North and the Nelson: about 1,150 river miles. Past the border it runs north through Canada to Hudson Bay.
Lake on the way: Lake Winnipeg.
430 miles of the trip are on the Red River of the North.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Ayr; river miles along the main stem, rounded.
Ayr has a warm-summer humid continental climate. Summer afternoons average 81° in July; winter nights fall to about −1° in January. A normal year brings about 37 inches of snow; with the rain, that comes to about 24 inches of water.
On November 14 Ayr normally reaches 38° and falls to 20°. The record high is 66°, in 1999; the record low −2°, in 2014. The most rain on this date, 0.41 in, fell in 1997.
Normals 1991–2020 and records since 1984 at Casselton Agronomy Farm, 17 miles southeast, 260 ft lower. NOAA, through RCC-ACIS.
