The Somerville 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.
Chance of showers
Showers likely
Chance of showers
Sunny; warmer
Mostly cloudy
Partly cloudy
Partly cloudy
18° on Nov. 13, 2019, the coldest reading for this week of the year since 1963. Next is 19° in 2018.
Somerville’s center stands about 260 ft above sea level. Within three miles the land runs from 200 ft to 320 ft, a difference of 120 ft: gently rolling country. The highest named summit within 15 miles is Homeymeyer Mountain, about 470 ft, 15 miles south-southwest.
Under the town center the state geologic map shows Manning Formation (sandstone-mudstone), from the Late Eocene, 34 to 38 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 64×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Claystone, sandstone. Age: Eocene, 34 to 56 million years old. About 5 mi of the line.
Mudstone, sand. Age: Oligocene, 23 to 34 million years old. About 4 mi of the line.
Sand. Age: Pleistocene to Holocene, less than 2.6 million years old. About 4 mi of the line.
Sandstone-mudstone. Age: Late Eocene, 34 to 38 million years old. About 3 mi of the line.
Sandstone, clay. Age: Miocene, 5.3 to 23 million years old. About 2 mi of the line.
Fine-detrital, coarse-detrital. Age: Holocene, less than 12,000 years old. About 1 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 Somerville reaches the Gulf of America by way of Thompson Creek, Old Yegua Creek, Yegua Creek and the Brazos: about 260 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Somerville; river miles along the main stem, rounded.
Somerville has a humid subtropical climate. Summer afternoons average 98° in August; winter nights fall to about 35° in January. About 41 inches of rain fall in a normal year.
On November 14 Somerville normally reaches 73° and falls to 45°. The record high is 89°, in 2005; the record low 19°, in 2018. The most rain on this date, 2.10 in, fell in 1993.
Normals 1991–2020 and records since 1963 at Somerville Dam, here. NOAA, through RCC-ACIS.
