The Sebastian 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
Chance of showers; warmer
Chance of showers; cooler
Partly cloudy
Partly cloudy; warmer
Partly cloudy
Mostly sunny
28° on Nov. 14, 2018, the coldest reading for this week of the year since 1910. Next is 29° in 1920.
Sebastian’s center stands about 40 ft above sea level. Within three miles the land runs from 30 ft to 50 ft, a difference of 20 ft: nearly flat ground.
Under the town center the state geologic map shows Beaumont Formation, areas predominantly sand, from the Pleistocene, less than 2.6 million years old.
The section below crosses 6 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.
Sand. Age: Pleistocene, less than 2.6 million years old. About 11 mi of the line.
Fine-detrital, sand. Age: Pleistocene to Holocene, less than 2.6 million years old. About 6 mi of the line.
Clay, sandstone. Age: Miocene, 5.3 to 23 million years old. About 3 mi of the line.
Clay, silt. Age: Pleistocene, less than 2.6 million years old. About 2 mi of the line.
Sand. Age: Holocene, less than 12,000 years old. About 1 mi of the line.
Silt, sand, clay. Age: Pleistocene, less than 2.6 million 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.
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.
Sebastian has a humid subtropical climate. Summer afternoons average 98° in August; winter nights fall to about 48° in January. About 26 inches of rain fall in a normal year.
On November 14 Sebastian normally reaches 80° and falls to 56°. The record high is 93°, in 2005; the record low 28°, in 2018. The most rain on this date, 1.65 in, fell in 1916.
Normals 1991–2020 and records since 1910 at Raymondville, 8 miles north. NOAA, through RCC-ACIS.
