The Concord 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.
76° on Nov. 12, 2022, the hottest reading for this week of the year since 1949. Next is 75° in 2020.
Concord’s center stands about 140 ft above sea level. Within three miles the land runs from 110 ft to 350 ft, a difference of 240 ft: rolling country. The highest named summit within 15 miles is Wataquadock Hill, about 680 ft, 15 miles west.
Under the town center the state geologic map shows Straw Hollow Diorite and Assabet Quartz Diorite undifferentiated (diorite, quartz-diorite), from the Silurian, 428 to 445 million years old.
The section below crosses 15 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 36×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Schist, gneiss. Age: Neoproterozoic to Ordovician, 445 to 1,000 million years old. About 7 mi of the line.
Diorite, gabbro. Age: Neoproterozoic, 542 to 1,000 million years old. About 4 mi of the line.
Granite, pegmatite. Age: Ordovician to Silurian, 422 to 487 million years old. About 3 mi of the line.
Argillite. Age: Neoproterozoic to Early Cambrian, 521 to 1,000 million years old. About 2 mi of the line.
Metavolcanic. Age: Neoproterozoic, 542 to 1,000 million years old. About 2 mi of the line.
Diorite, quartz-diorite. Age: Silurian, 428 to 445 million 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. 9 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 Concord reaches the Atlantic Ocean by way of the Assabet, the Concord and the Merrimack: about 55 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Concord; river miles along the main stem, rounded.
Concord has a hot-summer humid continental climate. Summer afternoons average 85° in July; winter nights fall to about 18° in January. About 43 inches of rain fall in a normal year.
On November 14 Concord normally reaches 53° and falls to 33°. The record high is 70°, in 1959; the record low 14°, in 2019. The most rain on this date, 3.12 in, fell in 2009.
Normals 1991–2020 and records since 1949 at Bedford Hanscom Field, 3 miles east. NOAA, through RCC-ACIS.