The San Leon 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; warmer
Showers likely; cooler
Mostly sunny
Mostly cloudy
Partly cloudy
Partly cloudy
30° on Nov. 15, 2018, the coldest reading for this week of the year since 1990. Next is 31° in 2019.
San Leon’s center stands about 7 ft above sea level. Within three miles the land runs from 0 ft to 20 ft, a difference of 20 ft: nearly flat ground. Open water lies within three miles.
The section below crosses 2 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.
Clay, silt. Age: Pleistocene, less than 2.6 million years old. About 8 mi of the line.
Sand. Age: Pleistocene, less than 2.6 million years old. About 4 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 San Leon reaches Galveston Bay and the Gulf of America by way of Factory Bayou: about 1 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of San Leon; river miles along the main stem, rounded.
San Leon has a humid subtropical climate. Summer afternoons average 92° in July; winter nights fall to about 46° in January. About 60 inches of rain fall in a normal year.
On November 14 San Leon normally reaches 73° and falls to 54°. The record high is 85°, in 2007; the record low 32°, in 2018. The most rain on this date, 2.47 in, fell in 1998.
Normals 1991–2020 and records since 1990 at Houston Nwso, 10 miles west. NOAA, through RCC-ACIS.
