The Chebeague Island 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.
73° on Nov. 12, 2022, the hottest reading for this week of the year since 1871. Next is 72° in 1896.
Chebeague Island’s center stands about 100 ft above sea level. Within three miles the land runs from 0 ft to 200 ft, a difference of 200 ft: rolling country. Open water lies within three miles. The highest named summit within 15 miles is Atherton Hill, about 610 ft, 14 miles west-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 48×. 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 5 mi of the line.
Granite. Age: Carboniferous, 299 to 359 million years old. About 2 mi of the line.
Felsic-volcanic, mafic-volcanic. Age: Neoproterozoic to Ordovician, 445 to 1,000 million years old. About 0.5 mi of the line.
Mudstone. Age: Neoproterozoic to Ordovician, 445 to 1,000 million years old. About 0.5 mi of the line.
Mudstone. Age: Neoproterozoic to Ordovician, 445 to 1,000 million years old. About 0.4 mi of the line.
Slate. Age: Neoproterozoic to Ordovician, 445 to 1,000 million years old. About 0.3 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale. 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.
Chebeague Island has a warm-summer humid continental climate. Summer afternoons average 80° in July; winter nights fall to about 16° in January. A normal year brings about 69 inches of snow; with the rain, that comes to about 48 inches of water.
On November 14 Chebeague Island normally reaches 49° and falls to 32°. The record high is 69°, in 1973; the record low 12°, in 1986. The most rain on this date, 5.03 in, fell in 2009.
Normals 1991–2020 and records since 1871 from the Portland Area threaded record (Portland Jetport, 12 miles southwest). NOAA, through RCC-ACIS.