The Hopatcong 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
Mostly sunny; warmer
Partly cloudy
Mostly sunny
Sunny
Mostly sunny
Mostly sunny
76° on Nov. 16, 1993, the hottest reading for this week of the year since 1893. Next is 74° in 1927.
Hopatcong’s center stands about 1,040 ft above sea level. Within three miles the land runs from 720 ft to 1,190 ft, a difference of 470 ft: hilly country. The highest named summit within 15 miles is Bowling Green Mountain, about 1,420 ft, 8 miles northeast.
Under the town center the state geologic map shows Pyroxene Syenite, from the Mesoproterozoic, 1 to 1.6 billion 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 23×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Age: Mesoproterozoic, 1 to 1.6 billion years old. About 4 mi of the line.
Dolostone. Age: Cambrian to Early Ordovician, 471 to 497 million years old. About 3 mi of the line.
Granite. Age: Mesoproterozoic, 1 to 1.6 billion years old. About 2 mi of the line.
Graywacke, siltstone. Age: Middle Ordovician to Late Ordovician, 445 to 471 million years old. About 2 mi of the line.
Syenite. Age: Mesoproterozoic, 1 to 1.6 billion years old. About 2 mi of the line.
Granite. Age: Mesoproterozoic, 1.1 to 1.1 billion 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. 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 Hopatcong reaches Delaware Bay and the Atlantic Ocean by way of the Musconetcong and the Delaware: about 190 river miles.
140 miles of the trip are on the Delaware.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Hopatcong; river miles along the main stem, rounded.
Hopatcong has a hot-summer humid continental climate. Summer afternoons average 83° in July; winter nights fall to about 19° in January. About 52 inches of rain fall in a normal year.
On November 14 Hopatcong normally reaches 52° and falls to 32°. The record high is 71°, in 1902; the record low 10°, in 1905. The most rain on this date, 1.37 in, fell in 1935.
Normals 1991–2020 and records since 1893 at Charlotteburg Reservoir, 14 miles east-northeast, 260 ft lower. NOAA, through RCC-ACIS.
