The Gap 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.
16° on Nov. 11, 2017, the coldest reading for this week of the year since 1992. Next is 19° in 1996.
Gap’s center stands about 480 ft above sea level. Within three miles the land runs from 390 ft to 830 ft, a difference of 440 ft: hilly country. The highest named summit within 15 miles is Welsh Mountain, about 1,080 ft, 9 miles north-northeast.
Under the town center the state geologic map shows Vintage Formation (dolostone), from the Cambrian, 487 to 542 million years old.
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 25×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Mica-schist, quartzite. Age: Paleozoic, 252 to 542 million years old. About 5 mi of the line.
Dolostone. Age: Cambrian, 487 to 542 million years old. About 4 mi of the line.
Schist, phyllite. Age: Paleozoic, 252 to 542 million years old. About 3 mi of the line.
Gneiss. Age: Precambrian. About 3 mi of the line.
Quartzite, schist. Age: Cambrian, 487 to 542 million years old. About 2 mi of the line.
Schist, phyllite. Age: Cambrian, 487 to 542 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 Gap reaches Chesapeake Bay and the Atlantic Ocean by way of Pequea Creek and the Susquehanna: about 70 river miles.
Lake on the way: Lake Aldred.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Gap; river miles along the main stem, rounded.
Gap has a hot-summer humid continental climate. Summer afternoons average 86° in July; winter nights fall to about 24° in January. A normal year brings about 34 inches of snow; with the rain, that comes to about 47 inches of water.
On November 14 Gap normally reaches 54° and falls to 37°. The record high is 70°, in 1993; the record low 25°, in 2004. The most rain on this date, 0.50 in, fell in 2008.
Normals 1991–2020 and records since 1992 at New Holland 2 SE, 6 miles north-northwest, 120 ft higher. NOAA, through RCC-ACIS.