The Johnstown 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
Mostly sunny
Partly cloudy
Partly cloudy
Mostly sunny; cooler
Partly cloudy
Chance of showers
69° on Nov. 15, 2016, the hottest reading for this week of the year since 1919. Next is 67° in 1956.
Johnstown’s center stands about 5,250 ft above sea level. Within three miles the land runs from 5,210 ft to 5,710 ft, a difference of 500 ft: hilly country. The highest named summit within 15 miles is Winkleman Dome, about 6,210 ft, 11 miles west.
Under the town center the state geologic map shows Alluvium and Colluvium (clay, silt, sand), from the Pleistocene to Holocene, less than 2.6 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 21×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Clay, silt, sand. Age: Pleistocene to Holocene, less than 2.6 million years old. About 11 mi of the line.
Claystone. Age: Eocene, 34 to 56 million years old. About 7 mi of the line.
Shale, siltstone. Age: Late Cretaceous, 78 to 83 million years old. About 3 mi of the line.
Gravel. Age: Pleistocene to Holocene, less than 2.6 million years old. About 3 mi of the line.
Sandstone, shale. Age: Paleocene, 56 to 66 million years old. About 0.3 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 Johnstown reaches the Gulf of America by way of the Wind River, the Bighorn, the Yellowstone, the Missouri and the Mississippi: about 3,390 river miles.
Lakes on the way: Lake Oahe, Lake Sakakawea, Lake Sharpe and Lake Francis Case.
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 Johnstown; river miles along the main stem, rounded.
Johnstown has a cold semi-arid climate. Summer afternoons average 86° in July; winter nights fall to about 9° in December. A normal year brings about 28 inches of snow; with the rain, that comes to about 9 inches of water.
On November 14 Johnstown normally reaches 45° and falls to 20°. The record high is 68°, in 2016; the record low −17°, in 1959. The most rain on this date, 0.17 in, fell in 1958.
Normals 1991–2020 and records since 1919 at Pavillion, 9 miles north, 230 ft higher. NOAA, through RCC-ACIS.
