The Mahwah 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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77° on Nov. 15, 1993, the hottest reading for this week of the year since 1969. Next is 76° in 1973.
Mahwah’s center stands about 340 ft above sea level. Within three miles the land runs from 260 ft to 860 ft, a difference of 600 ft: hilly country. The highest named summit within 15 miles is Taylor Mountain, about 1,510 ft, 14 miles northwest.
Under the town center the state geologic map shows Passaic Formation Quatzite-clast Conglomerate facies (conglomerate, sandstone), from the Early Jurassic to Late Jurassic, 145 to 202 million years old.
The section below crosses 10 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 15×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Conglomerate, sandstone. Age: Early Jurassic to Late Jurassic, 145 to 202 million years old. About 5 mi of the line.
Gneiss. Age: Mesoproterozoic, 1 to 1.6 billion years old. About 5 mi of the line.
Conglomerate-sandstone. Age: Early Jurassic to Late Jurassic, 145 to 202 million years old. About 4 mi of the line.
Sandstone, siltstone. Age: Early Jurassic to Late Jurassic, 145 to 202 million years old. About 4 mi of the line.
Granite, gneiss. Age: Mesoproterozoic, 1 to 1.6 billion years old. About 2 mi of the line.
Gneiss. Age: Mesoproterozoic, 1 to 1.6 billion 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. 4 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 Mahwah reaches New York Harbor and the Atlantic Ocean by way of Darlington Brook, the Ramapo, the Pompton and the Passaic: about 50 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Mahwah; river miles along the main stem, rounded.
Mahwah has a humid subtropical climate. Summer afternoons average 87° in July; winter nights fall to about 26° in January. About 46 inches of rain fall in a normal year.
On November 14 Mahwah normally reaches 56° and falls to 39°. The record high is 72°, in 1973; the record low 18°, in 1986. The most rain on this date, 0.96 in, fell in 1979.
Normals 1991–2020 and records since 1969 at Teterboro Airport, 17 miles south-southeast, 340 ft lower. NOAA, through RCC-ACIS.
