The So-Hi 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.
18° on Nov. 17, 1958, the coldest reading for this week of the year since 1901. Next is 19° in 1985.
So-Hi’s center stands about 3,460 ft above sea level. Within three miles the land runs from 2,920 ft to 5,080 ft, a difference of 2,160 ft: mountain country. The highest named summit within 15 miles is Cherum Peak, about 6,890 ft, 10 miles north.
Under the town center the state geologic map shows Quaternary surficial deposits, undivided (sand, silt, clay), from the Pleistocene to Holocene, less than 2 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.
Sand, silt, clay. Age: Pleistocene to Holocene, less than 2 million years old. About 12 mi of the line.
Granite, granodiorite, tonalite. Age: Paleoproterozoic, 1.6 to 1.8 billion years old. About 6 mi of the line.
Granite, granodiorite, diorite. Age: Late Cretaceous to Early Eocene, 50 to 82 million years old. About 3 mi of the line.
Metasedimentary, metavolcanic, gneiss. Age: Paleoproterozoic, 1.6 to 1.8 billion years old. About 2 mi of the line.
Basalt, andesite, dacite. Age: Middle Eocene to Late Miocene, 11 to 38 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 So-Hi reaches the Gulf of California by way of Thirteenmile Wash, Sacramento Wash and the Colorado: about 390 river miles.
Lakes on the way: Lake Havasu and Lost Lake.
290 miles of the trip are on the Colorado.
Seldom reaches the sea. Dams and canals now take nearly all of the Colorado before its old delta in Mexico.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of So-Hi; river miles along the main stem, rounded.
So-Hi has a cold desert climate. Summer afternoons average 99° in July; winter nights fall to about 30° in December. About 8 inches of rain fall in a normal year.
On November 14 So-Hi normally reaches 67° and falls to 37°. The record high is 82°, in 1999; the record low 24°, in 1964. The most rain on this date, 0.76 in, fell in 1946.
Normals 1991–2020 and records since 1901 from the Kingman Area threaded record (Kingman Airport, 12 miles east). NOAA, through RCC-ACIS.