The Green Acres 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.
93° on Nov. 15, 1999, the hottest reading for this week of the year since 1948. Next is 92° in 1989.
Green Acres’s center stands about 1,560 ft above sea level. Within three miles the land runs from 1,460 ft to 2,340 ft, a difference of 880 ft: hilly country. The highest named summit within 15 miles is Angelus Hill, about 4,050 ft, 14 miles east-northeast.
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.
Coarse-detrital. Age: Pleistocene to Holocene, less than 2.6 million years old. About 13 mi of the line.
Plutonic, gneiss. Age: Paleoproterozoic to Late Cretaceous, 66 to 2,500 million years old. About 4 mi of the line.
Diorite, gabbro. Age: Triassic to Cretaceous, 66 to 252 million years old. About 4 mi of the line.
Argillite. Age: Paleozoic to Late Jurassic, 145 to 542 million years old. About 2 mi of the line.
Tonalite. Age: Middle Jurassic to Late Cretaceous, 66 to 175 million years old. About 0.6 mi of the line.
Sandstone, conglomerate. Age: Miocene to Pleistocene, less than 23 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 Green Acres reaches the Pacific Ocean by way of the San Jacinto, Temescal Wash and the Santa Ana: about 80 river miles.
Often dry. About 80% of the way is mapped as streams that run only after rain or snowmelt; the water makes the whole trip in floods.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Green Acres; river miles along the main stem, rounded.
Green Acres has a hot semi-arid climate. Summer afternoons average 97° in August; winter nights fall to about 39° in December. About 12 inches of rain fall in a normal year.
On November 14 Green Acres normally reaches 73° and falls to 45°. The record high is 91°, in 2021; the record low 30°, in 2000. The most rain on this date, 0.29 in, fell in 1997.
Normals 1991–2020 and records since 1948 at San Jacinto, 7 miles northeast. NOAA, through RCC-ACIS.