The Clay 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
Showers likely
Showers likely
Chance of showers
Showers likely
Showers likely
Partly cloudy
26° on Nov. 17, 1961, the coldest reading for this week of the year since 1856. Next is 27° in 1958.
Clay’s center stands about 100 ft above sea level. Within three miles the land runs from 80 ft to 230 ft, a difference of 150 ft: gently rolling country. The highest named summit within 15 miles is Buena Vista Peaks, about 820 ft, 14 miles east-southeast.
Under the town center the state geologic map shows Older Quaternary alluvium and marine deposits (coarse-detrital), from the Pleistocene, 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 40×. 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 9 mi of the line.
Sandstone, conglomerate. Age: Miocene to Pleistocene, less than 23 million years old. About 7 mi of the line.
Sandstone. Age: Eocene, 34 to 56 million years old. About 3 mi of the line.
Sandstone, conglomerate. Age: Oligocene to Pleistocene, less than 34 million years old. About 3 mi of the line.
Coarse-detrital. Age: Pleistocene, less than 2.6 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 Clay reaches San Francisco Bay and the Pacific Ocean by way of Griffith Creek, Skunk Creek, the Cosumnes, the Mokelumne, the South Mokelumne, the San Joaquin and New York Slough: about 65 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Clay; river miles along the main stem, rounded.
Clay has a hot-summer Mediterranean climate. Summer afternoons average 93° in July; winter nights fall to about 38° in December. About 18 inches of rain fall in a normal year.
On November 14 Clay normally reaches 66° and falls to 43°. The record high is 81°, in 2010; the record low 27°, in 1978. The most rain on this date, 0.88 in, fell in 1963.
Normals 1991–2020 and records since 1856 from the Sacramento Area threaded record (Sacramento Airport Asos, 22 miles west-northwest). NOAA, through RCC-ACIS.
