The Peterborough 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
Partly cloudy; warmer
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Mostly sunny
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69° on Nov. 11, 2020, the hottest reading for this week of the year since 1906. Next is 67° in 2022.
Peterborough’s center stands about 740 ft above sea level. Within three miles the land runs from 720 ft to 1,330 ft, a difference of 610 ft: hilly country. The highest named summit within 15 miles is Monadnock Mountain, about 3,130 ft, 8 miles west.
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 10 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 9×. 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 8 mi of the line.
Pelitic-schist, metasandstone. Age: Silurian, 434 to 445 million years old. About 5 mi of the line.
Metaclastic. Age: Early Devonian, 394 to 422 million years old. About 3 mi of the line.
Metaclastic. Age: Silurian, 434 to 445 million years old. About 2 mi of the line.
Metasedimentary. Age: Early Devonian, 394 to 422 million years old. About 2 mi of the line.
Granodiorite. Age: Early Devonian, 394 to 422 million years old. About 0.9 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 Peterborough reaches the Atlantic Ocean by way of Nubanusit Brook, the Contoocook and the Merrimack: about 160 river miles.
100 miles of the trip are on the Merrimack.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Peterborough; river miles along the main stem, rounded.
Peterborough has a warm-summer humid continental climate. Summer afternoons average 80° in July; winter nights fall to about 14° in January. A normal year brings about 75 inches of snow; with the rain, that comes to about 49 inches of water.
Normals 1991–2020 and records since 1906 at Ashburnham, 18 miles south, 370 ft higher. NOAA, through RCC-ACIS.
