The Jansen 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.
Chance of showers
Partly cloudy
Mostly sunny; warmer
Partly cloudy
Mostly sunny
Partly cloudy
Mostly sunny
78° on Nov. 16, 1999, the hottest reading for this week of the year since 1989. Next is 77° in 1989.
Jansen’s center stands about 6,090 ft above sea level. Within three miles the land runs from 5,980 ft to 6,800 ft, a difference of 820 ft: hilly country. The highest named summit within 15 miles is Fishers Peak, about 9,620 ft, 6 miles southeast.
Under the town center the state geologic map shows Pierre Shale, undivided, from the Late Cretaceous, 66 to 100 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 5×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Arkose, siltstone, shale. Age: Late Cretaceous to Paleocene, 56 to 100 million years old. About 8 mi of the line.
Basalt. Age: Miocene to Pliocene, 2.6 to 23 million years old. About 6 mi of the line.
Conglomerate, sandstone, shale. Age: Paleocene, 56 to 66 million years old. About 5 mi of the line.
Shale, sandstone. Age: Late Cretaceous, 66 to 100 million years old. About 4 mi of the line.
Shale. Age: Late Cretaceous, 66 to 100 million years old. About 1 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 Jansen reaches the Gulf of America by way of the Purgatoire, the Arkansas and the Mississippi: about 1,910 river miles.
Lakes on the way: Murray Lake and Ozark Lake.
850 miles of the trip are on the Arkansas.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Jansen; river miles along the main stem, rounded.
Jansen has a warm-summer humid continental climate. Summer afternoons average 87° in July; winter nights fall to about 15° in January. A normal year brings about 48 inches of snow; with the rain, that comes to about 17 inches of water.
On November 14 Jansen normally reaches 56° and falls to 24°. The record high is 77°, in 2007; the record low 0°, in 2014. The most rain on this date, 0.56 in, fell in 1993.
Normals 1991–2020 and records since 1989 at Trinidad Lake, here, 220 ft higher. NOAA, through RCC-ACIS.
