The Jefferson 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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−4° on Nov. 17, 2019, the coldest reading for this week of the year since 1996. Next is −1° in 1996.
Jefferson’s center stands about 1,390 ft above sea level. Within three miles the land runs from 1,030 ft to 3,660 ft, a difference of 2,630 ft: mountain country. The highest named summit within 15 miles is Mount Washington, about 6,260 ft, 13 miles southeast.
Under the town center the state geologic map shows Hornblende quartz monzonite (quartz-monzonite), from the Late Ordovician, 445 to 459 million years old.
The section below crosses 11 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 4×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Granite. Age: Late Ordovician to Silurian, 438 to 446 million years old. About 4 mi of the line.
Quartz-monzonite. Age: Late Ordovician, 445 to 459 million years old. About 4 mi of the line.
Metasandstone, metasiltstone, phyllite. Age: Middle Cambrian to Early Ordovician, 485 to 500 million years old. About 3 mi of the line.
Quartz-syenite, syenite. Age: Late Ordovician, 445 to 459 million years old. About 3 mi of the line.
Granite. Age: Late Ordovician, 445 to 459 million years old. About 2 mi of the line.
Metagraywacke. Age: Early Devonian, 410 to 414 million 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. 5 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 Jefferson reaches Long Island Sound and the Atlantic Ocean by way of the Israel and the Connecticut: about 330 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Jefferson; river miles along the main stem, rounded.
Jefferson has a warm-summer humid continental climate. Summer afternoons average 80° in July; winter nights fall to about 5° in January. About 37 inches of rain fall in a normal year.
Normals 1991–2020 and records since 1996 at Whitefield Mount Washington Regional Airport, 5 miles southwest, 340 ft lower. NOAA, through RCC-ACIS.
