The Chalfont 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.
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75° on Nov. 11, 2020, the hottest reading for this week of the year since 1948. Next is 72° in 2005.
Chalfont’s center stands about 280 ft above sea level. Within three miles the land runs from 220 ft to 610 ft, a difference of 390 ft: rolling country. The highest named summit within 15 miles is Haycock Mountain, about 980 ft, 14 miles north.
Under the town center the state geologic map shows Lockatong Formation (argillite), from the Triassic, 202 to 252 million years old.
The section below crosses 5 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 40×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Argillite. Age: Triassic, 202 to 252 million years old. About 10 mi of the line.
Mudstone. Age: Triassic, 202 to 252 million years old. About 7 mi of the line.
Arkose. Age: Triassic, 202 to 252 million years old. About 6 mi of the line.
Dolostone. Age: Cambrian, 487 to 542 million years old. About 0.9 mi of the line.
Quartzite, schist. Age: Cambrian, 487 to 542 million years old. About 0.4 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 Chalfont reaches Delaware Bay and the Atlantic Ocean by way of West Branch Neshaminy Creek, Neshaminy Creek and the Delaware: about 120 river miles.
85 miles of the trip are on the Delaware.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Chalfont; river miles along the main stem, rounded.
Chalfont has a hot-summer humid continental climate. Summer afternoons average 85° in July; winter nights fall to about 19° in January. A normal year brings about 22 inches of snow; with the rain, that comes to about 52 inches of water.
On November 14 Chalfont normally reaches 54° and falls to 32°. The record high is 66°, in 2010; the record low 18°, in 1996. The most rain on this date, 0.55 in, fell in 2008.
Normals 1991–2020 and records since 1948 at Sellersville, 7 miles northwest. NOAA, through RCC-ACIS.
