The Mont Vernon 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.
Mostly cloudy
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74° on Nov. 11, 2020, the hottest reading for this week of the year since 1885. Next is 74° in 2022.
Mont Vernon’s center stands about 820 ft above sea level. Within three miles the land runs from 270 ft to 970 ft, a difference of 700 ft: hilly country. The highest named summit within 15 miles is Pack Monadnock Mountain, about 2,270 ft, 11 miles west-southwest.
Under the town center the state geologic map shows Spaulding Tonalite (quartz-diorite, tonalite, granodiorite), from the Early Devonian, 394 to 422 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 11×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Quartz-diorite, tonalite, granodiorite. Age: Early Devonian, 394 to 422 million years old. About 14 mi of the line.
Gneiss, biotite-schist, granofels. Age: Neoproterozoic, 542 to 1,000 million years old. About 6 mi of the line.
Pelitic-schist, metasandstone. Age: Silurian, 434 to 445 million years old. About 3 mi of the line.
Metasandstone. Age: Silurian, 434 to 445 million years old. About 1 mi of the line.
Quartzite, metasedimentary. Age: Silurian, 422 to 445 million years old. About 0.3 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 Mont Vernon reaches the Atlantic Ocean by way of Black Brook, Purgatory Brook, the Souhegan and the Merrimack: about 85 river miles.
60 miles of the trip are on the Merrimack.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Mont Vernon; river miles along the main stem, rounded.
Mont Vernon has a hot-summer humid continental climate. Summer afternoons average 84° in July; winter nights fall to about 17° in January. About 40 inches of rain fall in a normal year.
On November 14 Mont Vernon normally reaches 51° and falls to 33°. The record high is 66°, in 2011; the record low 16°, in 2019. The most rain on this date, 1.77 in, fell in 2009.
Normals 1991–2020 and records since 1885 from the Manchester Area threaded record (Manchester Airport, 12 miles east-northeast, 590 ft lower). NOAA, through RCC-ACIS.
