The Markham 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
Showers likely; cooler
Mostly sunny
Mostly cloudy; warmer
Partly cloudy
Partly cloudy
89° on Nov. 13, 1969, the hottest reading for this week of the year since 1909. Next is 88° in 1916.
Markham’s center stands about 60 ft above sea level. Within three miles the land runs from 40 ft to 70 ft, a difference of 30 ft: nearly flat ground.
The section below crosses 3 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 14 mi of the line.
Clay, silt. Age: Pleistocene, less than 2.6 million years old. About 8 mi of the line.
Fine-detrital, coarse-detrital. Age: Holocene, less than 12,000 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.
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 Markham reaches the Gulf of America by way of Wilson Creek and the Tres Palacios: about 30 river miles.
Often dry. About 30% of the way is mapped as streams that run only after rain or snowmelt; the water makes the whole trip in floods.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Markham; river miles along the main stem, rounded.
Markham has a humid subtropical climate. Summer afternoons average 92° in August; winter nights fall to about 43° in January. About 49 inches of rain fall in a normal year.
On November 14 Markham normally reaches 72° and falls to 52°. The record high is 86°, in 1955; the record low 30°, in 2019. The most rain on this date, 2.05 in, fell in 1961.
Normals 1991–2020 and records since 1909 at Bay City Waterworks, 6 miles east-northeast. NOAA, through RCC-ACIS.
