The Grafton 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.
Grafton’s center stands about 1,070 ft above sea level. Within three miles the land runs from 1,050 ft to 1,080 ft, a difference of 30 ft: nearly flat ground.
Under the town center the state geologic map shows Undifferentiated (conglomerate, sandstone, mudstone), from the Late Cretaceous, 72 to 100 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 64×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Orthogneiss. Age: Paleoarchean to Mesoarchean, 2.8 to 3.6 billion years old. About 7 mi of the line.
Orthogneiss, migmatite. Age: Paleoarchean to Mesoarchean, 2.8 to 3.6 billion years old. About 6 mi of the line.
Tonalite, granodiorite, diorite. Age: Neoarchean, 2.5 to 2.8 billion years old. About 6 mi of the line.
Conglomerate, sandstone, mudstone. Age: Late Cretaceous, 72 to 100 million years old. About 5 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 Grafton reaches the Gulf of America by way of High Island Creek, the Minnesota and the Mississippi: about 1,940 river miles.
Lake on the way: Lake Pepin.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Grafton; river miles along the main stem, rounded.
Grafton 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 Grafton 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, 19 miles east-southeast. NOAA, through RCC-ACIS.