The Sebastopol 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.
Partly cloudy
Showers likely
Chance of showers
Showers likely
Showers likely
Showers likely
Partly cloudy
22° on Nov. 17, 1961, the coldest reading for this week of the year since 1926. Next is 22° in 1978.
Sebastopol’s center stands about 130 ft above sea level. Within three miles the land runs from 50 ft to 490 ft, a difference of 440 ft: hilly country. The highest named summit within 15 miles is Sonoma Mountain, about 2,290 ft, 15 miles east-southeast.
Under the town center the state geologic map shows Pliocene marine rocks (sandstone, mudstone), from the Miocene to Pleistocene, less than 23 million years old.
The section below crosses 9 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 15×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Sandstone, mudstone. Age: Miocene to Pleistocene, less than 23 million years old. About 6 mi of the line.
Coarse-detrital. Age: Pleistocene to Holocene, less than 2.6 million years old. About 4 mi of the line.
Dacite. Age: Late Miocene to Late Pliocene, 3 to 7 million years old. About 4 mi of the line.
Melange. Age: Jurassic to Cretaceous, 66 to 202 million years old. About 4 mi of the line.
Coarse-detrital. Age: Pleistocene, less than 2.6 million years old. About 2 mi of the line.
Serpentinite. Age: Middle Jurassic to Late Jurassic, 145 to 175 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. 3 smaller units 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 Sebastopol reaches the Pacific Ocean by way of the Laguna de Santa Rosa, Mark West Creek and the Russian: about 35 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Sebastopol; river miles along the main stem, rounded.
Sebastopol has a warm-summer Mediterranean climate. Summer afternoons average 84° in August; winter nights fall to about 37° in January. About 40 inches of rain fall in a normal year.
On November 14 Sebastopol normally reaches 67° and falls to 40°. The record high is 85°, in 2008; the record low 25°, in 1985. The most rain on this date, 2.44 in, fell in 1972.
Normals 1991–2020 and records since 1926 at Graton, 3 miles northwest. NOAA, through RCC-ACIS.
