The Calmar 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.
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Showers likely
75° on Nov. 13, 1999, the hottest reading for this week of the year since 1893. Next is 73° in 1953.
Calmar’s center stands about 1,250 ft above sea level. Within three miles the land runs from 1,070 ft to 1,280 ft, a difference of 210 ft: rolling country.
Under the town center the state geologic map shows Wapsipinicon Group (dolostone, limestone), from the Middle Devonian, 384 to 394 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 46×. 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, dolostone. Age: Late Ordovician, 447 to 454 million years old. About 19 mi of the line.
Dolostone, limestone. Age: Middle Devonian, 384 to 394 million years old. About 5 mi of the line.
Dolostone, limestone. Age: Late Ordovician, 447 to 459 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 Calmar reaches the Gulf of America by way of the Turkey and the Mississippi: about 1,690 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Calmar; river miles along the main stem, rounded.
Calmar has a hot-summer humid continental climate. Summer afternoons average 84° in July; winter nights fall to about 10° in January. A normal year brings about 38 inches of snow; with the rain, that comes to about 38 inches of water.
On November 14 Calmar normally reaches 47° and falls to 29°. The record high is 71°, in 2025; the record low −7°, in 1916. The most rain on this date, 1.08 in, fell in 1902.
Normals 1991–2020 and records since 1893 at Decorah, 9 miles north-northeast, 390 ft lower. NOAA, through RCC-ACIS.
