The North Londonderry 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
Partly cloudy; warmer
Partly cloudy
Sunny
Sunny
Mostly sunny
Mostly sunny
75° on Nov. 15, 1993, the hottest reading for this week of the year since 1948. Next is 74° in 1973.
North Londonderry’s center stands about 150 ft above sea level. Within three miles the land runs from 350 ft to 610 ft, a difference of 260 ft: rolling country. The highest named summit within 15 miles is Stony Mountain, about 1,710 ft, 12 miles northwest.
The section below crosses 17 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 12×. 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. Age: Ordovician, 445 to 487 million years old. About 7 mi of the line.
Sandstone. Age: Triassic, 202 to 252 million years old. About 3 mi of the line.
Arkose. Age: Triassic, 202 to 252 million years old. About 3 mi of the line.
Basalt. Age: Jurassic, 145 to 202 million years old. About 2 mi of the line.
Shale, siltstone. Age: Ordovician, 445 to 487 million years old. About 1 mi of the line.
Limestone. Age: Ordovician, 445 to 487 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. 11 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 North Londonderry reaches Chesapeake Bay and the Atlantic Ocean by way of Killinger Creek, Quittapahilla Creek, Swatara Creek and the Susquehanna: about 90 river miles.
Lake on the way: Lake Aldred.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of North Londonderry; river miles along the main stem, rounded.
North Londonderry has a hot-summer humid continental climate. Summer afternoons average 84° in July; winter nights fall to about 22° in January. A normal year brings about 24 inches of snow; with the rain, that comes to about 46 inches of water.
On November 14 North Londonderry normally reaches 53° and falls to 34°. The record high is 72°, in 1989; the record low 17°, in 1986. The most rain on this date, 1.69 in, fell in 1972.
Normals 1991–2020 and records since 1948 at Lebanon 2 W, 6 miles east, 300 ft higher. NOAA, through RCC-ACIS.
