The Washington 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.
83° on Nov. 12, 1934, the hottest reading for this week of the year since 1893. Next is 82° in 1953.
Washington’s center stands about 2,800 ft above sea level. Within three miles the land runs from 2,590 ft to 3,540 ft, a difference of 950 ft: steep hill country. The highest named summit within 15 miles is Signal Peak, about 10,360 ft, 13 miles north.
Under the town center the state geologic map shows Alluvium and colluvium (unconsolidated), from the Quaternary, less than 2.6 million years old.
The section below crosses 10 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.
Unconsolidated. Age: Quaternary, less than 2.6 million years old. About 9 mi of the line.
Arenite, sandstone-mudstone. Age: Early Jurassic to Middle Jurassic, 164 to 202 million years old. About 6 mi of the line.
Sandstone-mudstone, sandstone. Age: Late Cretaceous, 72 to 94 million years old. About 2 mi of the line.
Sand, silt, clay. Age: Pleistocene to Holocene, less than 2 million years old. About 2 mi of the line.
Sandstone, limestone. Age: Middle Jurassic, 164 to 175 million years old. About 1 mi of the line.
Sandstone, mudstone. Age: Middle Triassic to Late Triassic, 230 to 245 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. 4 smaller units along the line are not listed.
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 Washington reaches the Gulf of California by way of the Virgin and the Colorado: about 580 river miles.
Lakes on the way: Lake Mead, Lake Mohave and Lake Havasu.
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 Washington; river miles along the main stem, rounded.
Washington has a cold desert climate. Summer afternoons average 102° in July; winter nights fall to about 28° in January. About 9 inches of rain fall in a normal year, with about 1 inch of snow.
On November 14 Washington normally reaches 64° and falls to 35°. The record high is 82°, in 1953; the record low 14°, in 1898. The most rain on this date, 0.55 in, fell in 1909.
Normals 1991–2020 and records since 1893 at St. George, 5 miles west. NOAA, through RCC-ACIS.