The American Canyon 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.
3.27 inches of rain fell in two days, the most for this week of the year since records began in 1893. The next wettest, 3.07 inches, fell in 1942.
American Canyon’s center stands about 70 ft above sea level. Within three miles the land runs from 0 ft to 780 ft, a difference of 780 ft: hilly country. Open water lies within three miles. The highest named summit within 15 miles is Twin Sisters, about 2,230 ft, 10 miles north-northeast.
The section below crosses 7 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 10×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Dacite. Age: Late Miocene to Late Pliocene, 3 to 7 million years old. About 7 mi of the line.
Coarse-detrital. Age: Pleistocene to Holocene, less than 2.6 million years old. About 2 mi of the line.
Coarse-detrital. Age: Pleistocene, less than 2.6 million years old. About 2 mi of the line.
Sandstone, mudstone. Age: Oligocene to Pliocene, 2.6 to 34 million years old. About 2 mi of the line.
Mudstone, sandstone. Age: Paleocene to Oligocene, 23 to 66 million years old. About 1 mi of the line.
Coarse-detrital. Age: Quaternary, less than 2.6 million years old. About 0.6 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale. 1 smaller unit 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 American Canyon reaches San Francisco Bay and the Pacific Ocean by way of the Napa: about 10 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of American Canyon; river miles along the main stem, rounded.
American Canyon has a warm-summer Mediterranean climate. Summer afternoons average 84° in August; winter nights fall to about 40° in January. About 27 inches of rain fall in a normal year.
On November 14 American Canyon normally reaches 67° and falls to 44°. The record high is 86°, in 2008; the record low 28°, in 1978. The most rain on this date, 1.70 in, fell in 1972.
Normals 1991–2020 and records since 1893 at Napa State Hospital, 7 miles north. NOAA, through RCC-ACIS.