The Altona 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; warmer
Mostly cloudy
Mostly sunny
Mostly sunny
Partly cloudy
Partly cloudy
1° on Nov. 13, 2019, the coldest reading for this week of the year since 1945. Next is 10° in 1986.
Altona’s center stands about 650 ft above sea level. Within three miles the land runs from 480 ft to 1,010 ft, a difference of 530 ft: hilly country. The highest named summit within 15 miles is Ellenburg Mountain, about 2,710 ft, 12 miles southwest.
Under the town center the state geologic map shows Potsdam Sandstone, from the Cambrian, 487 to 497 million years old.
The section below crosses 4 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.
Sandstone. Age: Cambrian, 487 to 497 million years old. About 17 mi of the line.
Dolostone. Age: Cambrian to Early Ordovician, 471 to 542 million years old. About 4 mi of the line.
Gneiss. Age: Mesoproterozoic, 1 to 1.6 billion years old. About 2 mi of the line.
Charnockite, gneiss. Age: Mesoproterozoic, 1 to 1.6 billion 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.
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 Altona reaches the St. Lawrence River by way of Witherspoon Brook, the Great Chazy and the Richelieu: about 120 river miles. The St. Lawrence carries it on to the Atlantic.
Lake on the way: Lake Champlain.
80 miles of the trip are on the Richelieu.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Altona; river miles along the main stem, rounded.
Altona has a warm-summer humid continental climate. Summer afternoons average 81° in July; winter nights fall to about 10° in January. About 31 inches of rain fall in a normal year.
On November 14 Altona normally reaches 46° and falls to 29°. The record high is 64°, in 1959; the record low 11°, in 2019. The most rain on this date, 0.88 in, fell in 2009.
Normals 1991–2020 and records since 1945 from the Plattsburgh Area threaded record (Plattsburgh International Airport, 20 miles south-southeast, 480 ft lower). NOAA, through RCC-ACIS.
