The Green Isle 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.
74° on Nov. 16, 2001, the hottest reading for this week of the year since 1956. Next is 72° in 1999.
Green Isle’s center stands about 1,000 ft above sea level. Within three miles the land runs from 980 ft to 1,020 ft, a difference of 40 ft: nearly flat ground.
Under the town center the state geologic map shows Upper Cambrian (sandstone, siltstone, shale), 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 58×. 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, siltstone, shale. Age: Cambrian, 487 to 497 million years old. About 12 mi of the line.
Claystone, siltstone, sandstone. Age: Early Cretaceous, 100 to 113 million years old. About 8 mi of the line.
Dolostone, sandstone. Age: Early Ordovician, 471 to 487 million years old. About 3 mi of the line.
Sandstone, siltstone, shale. Age: Middle Cambrian to Cambrian, 487 to 521 million years old. About 0.7 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 Green Isle reaches the Gulf of America by way of Bevens Creek, the Minnesota and the Mississippi: about 1,900 river miles.
Lake on the way: Lake Pepin.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Green Isle; river miles along the main stem, rounded.
Green Isle has a cold desert climate. Summer afternoons average 82° in July; winter nights fall to about 6° in January. Barely 0.0 inches of rain fall in a normal year.
On November 14 Green Isle normally reaches 41° and falls to 26°. The record high is 69°, in 1990; the record low −5°, in 1959. The most rain on this date, 0.34 in, fell in 2024.
Normals 1991–2020 and records since 1956 at Gaylord, 13 miles southwest. NOAA, through RCC-ACIS.