The Groton 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
Mostly sunny; warmer
Mostly sunny
Sunny
Sunny
Mostly sunny
Mostly sunny
12° on Nov. 16, 1996, the coldest reading for this week of the year since 1956. Next is 14° in 1956.
Groton’s center stands about 80 ft above sea level. Within three miles the land runs from 0 ft to 240 ft, a difference of 240 ft: rolling country. Open water lies within three miles. The highest named summit within 15 miles is Chapel Hill, about 650 ft, 10 miles northwest.
The section below crosses 7 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 39×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Gneiss. Age: Neoproterozoic, 542 to 1,000 million years old. About 3 mi of the line.
Gneiss. Age: Neoproterozoic, 542 to 1,000 million years old. About 3 mi of the line.
Gneiss. Age: Neoproterozoic, 542 to 1,000 million years old. About 3 mi of the line.
Gneiss. Age: Neoproterozoic, 542 to 1,000 million years old. About 2 mi of the line.
Quartzite. Age: Neoproterozoic, 542 to 1,000 million years old. About 1 mi of the line.
Clay, sand, gravel. Age: Late Cretaceous, 66 to 100 million years old. About 0.7 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale. 1 smaller unit 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.
Rain that falls on Groton runs straight into Long Island Sound and the Atlantic Ocean.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Groton; river miles along the main stem, rounded.
Groton has a hot-summer humid continental climate. Summer afternoons average 84° in July; winter nights fall to about 21° in January. A normal year brings about 28 inches of snow; with the rain, that comes to about 52 inches of water.
On November 14 Groton normally reaches 54° and falls to 35°. The record high is 72°, in 1993; the record low 17°, in 1986. The most rain on this date, 2.25 in, fell in 1972.
Normals 1991–2020 and records since 1956 at Norwich Public Utility Plant, 12 miles north. NOAA, through RCC-ACIS.
