The Derby Line 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.
Chance of showers
Mostly cloudy
Mostly cloudy
Mostly sunny; warmer
Partly cloudy
Partly cloudy
Partly cloudy
69° on Nov. 11, 2020, the hottest reading for this week of the year since 1990. Next is 68° in 2002.
Derby Line’s center stands about 1,030 ft above sea level. Within three miles the land runs from 670 ft to 1,600 ft, a difference of 930 ft: steep hill country. The highest named summit within 15 miles is Middle Mountain, about 2,950 ft, 14 miles east-southeast.
The section below crosses 3 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 12×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Phyllite, limestone. Age: Silurian to Early Devonian, 394 to 425 million years old. About 4 mi of the line.
Granite, pegmatite. Age: Devonian, 359 to 422 million years old. About 4 mi of the line.
Quartzite. Age: Early Devonian, 394 to 422 million years old. About 4 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 Derby Line reaches the St. Lawrence River by way of the Johns, the Magog and the Saint-François: about 170 river miles. The St. Lawrence carries it on to the Atlantic.
Lake on the way: Lake Memphremagog.
120 miles of the trip are on the Saint-François.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Derby Line; river miles along the main stem, rounded.
Derby Line has a warm-summer humid continental climate. Summer afternoons average 76° in July; winter nights fall to about 3° in January. A normal year brings about 115 inches of snow; with the rain, that comes to about 45 inches of water.
On November 14 Derby Line normally reaches 42° and falls to 27°. The record high is 60°, in 2010; the record low −3°, in 2019. The most rain on this date, 0.31 in, fell in 2021.
Normals 1991–2020 and records since 1990 at Island Pond, 17 miles southeast, 170 ft higher. NOAA, through RCC-ACIS.
