The Irasburg 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.
Irasburg’s center stands about 930 ft above sea level. Within three miles the land runs from 790 ft to 1,440 ft, a difference of 650 ft: hilly country. The highest named summit within 15 miles is Jay Peak, about 3,810 ft, 15 miles northwest.
Under the town center the state geologic map shows Waits River Formation - Ayers Cliff member (metasandstone, metacarbonate, phyllite), from the Silurian to Early Devonian, 394 to 425 million years old.
The section below crosses 12 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 10×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Pegmatite. Age: Middle Devonian to Late Devonian, 367 to 385 million years old. About 5 mi of the line.
Granite, granodiorite. Age: Devonian, 359 to 422 million years old. About 3 mi of the line.
Metasandstone, metacarbonate, phyllite. Age: Silurian to Early Devonian, 394 to 425 million years old. About 3 mi of the line.
Phyllite, limestone. Age: Silurian to Early Devonian, 394 to 425 million years old. About 3 mi of the line.
Muscovite-schist, gneiss, quartzite. Age: Neoproterozoic to Early Cambrian, 521 to 1,000 million years old. About 3 mi of the line.
Phyllite. Age: Neoproterozoic to Cambrian, 487 to 1,000 million years old. About 2 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale. 6 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 Irasburg reaches the St. Lawrence River by way of the Black River, the Magog and the Saint-François: about 190 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 Irasburg; river miles along the main stem, rounded.
Irasburg 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 Irasburg 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, 19 miles east, 270 ft higher. NOAA, through RCC-ACIS.
