The Surprise 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.
95° on Nov. 13, 1999, the hottest reading for this week of the year since 1964. Next is 92° in 1967.
Surprise’s center stands about 1,360 ft above sea level. Within three miles the land runs from 1,280 ft to 1,450 ft, a difference of 170 ft: gently rolling country. The highest named summit within 15 miles is Barry Goldwater Peak, about 4,020 ft, 10 miles southwest.
Under the town center the state geologic map shows Late and middle Pleistocene surficial deposits (gravel, sand), from the Pleistocene, less than 0.8 million years old.
The section below crosses 6 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 9×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Gravel, sand. Age: Pleistocene, less than 0.8 million years old. About 13 mi of the line.
Metasedimentary, metavolcanic, gneiss. Age: Paleoproterozoic, 1.6 to 1.8 billion years old. About 5 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.
Granite. Age: Late Cretaceous to Early Eocene, 50 to 80 million years old. About 2 mi of the line.
Silt, clay. Age: Holocene, less than 10,000 years old. About 2 mi of the line.
Basalt. Age: Early Miocene to Late Miocene, 8 to 16 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 Surprise reaches the Gulf of California by way of the Beardsley Canal, the Hassayampa, the Gila and the Colorado: about 350 river miles.
170 miles of the trip are on the Gila.
Often dry. About 60% of the way is mapped as streams that run only after rain or snowmelt; the water makes the whole trip in floods.
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 Surprise; river miles along the main stem, rounded.
Surprise has a hot desert climate. Summer afternoons average 105° in July; winter nights fall to about 40° in December. About 8 inches of rain fall in a normal year.
On November 14 Surprise normally reaches 75° and falls to 48°. The record high is 94°, in 1999; the record low 38°, in 1985. The most rain on this date, 0.99 in, fell in 1993.
Normals 1991–2020 and records since 1964 at Youngtown, 10 miles east-southeast, 220 ft lower. NOAA, through RCC-ACIS.