The Monument Hills 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.
20° on Nov. 14, 1916, the coldest reading for this week of the year since 1893. Next is 22° in 1911.
Monument Hills’s center stands about 130 ft above sea level. Within three miles the land runs from 70 ft to 140 ft, a difference of 70 ft: gently rolling country. The highest named summit within 15 miles is Canterbury Mountain, about 2,470 ft, 13 miles west.
Under the town center the state geologic map shows Plio-Pleistocene and Pliocene loosely consolidated deposits (sandstone, conglomerate), from the Miocene to Pleistocene, less than 23 million years old.
The section below crosses 4 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 14×. 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 19 mi of the line.
Sandstone, conglomerate. Age: Miocene to Pleistocene, less than 23 million years old. About 4 mi of the line.
Sandstone, siltstone-mudstone. Age: Late Cretaceous, 66 to 100 million years old. About 1 mi of the line.
Andesite. Age: Late Oligocene to Pleistocene, 2 to 24 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 Monument Hills reaches San Francisco Bay and the Pacific Ocean by way of Willow Slough, Prospect Slough, Cache Slough and the Sacramento: about 60 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Monument Hills; river miles along the main stem, rounded.
Monument Hills has a hot-summer Mediterranean climate. Summer afternoons average 93° in July; winter nights fall to about 38° in January. About 19 inches of rain fall in a normal year.
On November 14 Monument Hills normally reaches 66° and falls to 43°. The record high is 83°, in 1894; the record low 20°, in 1916. The most rain on this date, 1.72 in, fell in 1981.
Normals 1991–2020 and records since 1893 at Davis 2 WSW Experiment Farm, 10 miles south-southeast. NOAA, through RCC-ACIS.