The Bethesda 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.
Mostly cloudy
Mostly cloudy; warmer
Partly cloudy
Sunny
Sunny
Partly cloudy
Mostly sunny
79° on Nov. 11, 2020, the hottest reading for this week of the year since 1987. Next is 75° in 1998.
Bethesda’s center stands about 1,240 ft above sea level. Within three miles the land runs from 1,010 ft to 1,340 ft, a difference of 330 ft: rolling country.
Under the town center the state geologic map shows Dunkard Group (mudstone, shale, siltstone), from the Carboniferous to Permian, 252 to 324 million years old.
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 34×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Shale, siltstone, mudstone. Age: Carboniferous, 299 to 324 million years old. About 11 mi of the line.
Mudstone, shale, siltstone. Age: Carboniferous to Permian, 252 to 324 million years old. About 9 mi of the line.
Shale, siltstone, mudstone. Age: Carboniferous, 299 to 324 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 Bethesda reaches the Gulf of America by way of the Bend Fork, Captina Creek, the Ohio and the Mississippi: about 1,870 river miles.
970 miles of the trip are on the Mississippi.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Bethesda; river miles along the main stem, rounded.
Bethesda has a hot-summer humid continental climate. Summer afternoons average 85° in July; winter nights fall to about 22° in January. About 42 inches of rain fall in a normal year.
On November 14 Bethesda normally reaches 54° and falls to 34°. The record high is 74°, in 1989; the record low 17°, in 2019. The most rain on this date, 1.10 in, fell in 1997.
Normals 1991–2020 and records since 1987 at Wheeling, 18 miles east, 600 ft lower. NOAA, through RCC-ACIS.
