The Alton 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.
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68° on Nov. 11, 2020, the hottest reading for this week of the year since 1925. Next is 68° in 2022.
Alton’s center stands about 180 ft above sea level. Within three miles the land runs from 110 ft to 270 ft, a difference of 160 ft: gently rolling country. The highest named summit within 15 miles is Cemetery Hill, about 740 ft, 14 miles east-northeast.
Under the town center the state geologic map shows Silurian - Ordovician Vassalboro Formation (sandstone), from the Late Ordovician to Silurian, 428 to 459 million years old.
The section below crosses 2 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 52×. 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: Late Ordovician to Silurian, 428 to 459 million years old. About 22 mi of the line.
Schist, slate. Age: Silurian, 428 to 445 million years old. About 3 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 Alton reaches the Atlantic Ocean by way of Tenmile Brook, the Birch Stream and the Penobscot: about 55 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Alton; river miles along the main stem, rounded.
Alton has a warm-summer humid continental climate. Summer afternoons average 80° in July; winter nights fall to about 9° in January. A normal year brings about 75 inches of snow; with the rain, that comes to about 42 inches of water.
On November 14 Alton normally reaches 46° and falls to 30°. The record high is 63°, in 2005; the record low 8°, in 2019. The most rain on this date, 1.56 in, fell in 2006.
Normals 1991–2020 and records since 1925 from the Bangor Area threaded record (Bangor International Airport, 17 miles south-southwest). NOAA, through RCC-ACIS.
