The Bluffton 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.
Partly cloudy
Mostly sunny; warmer
Partly cloudy
Mostly cloudy
Chance of showers
Partly cloudy
Showers likely
70° on Nov. 12, 2005, the hottest reading for this week of the year since 1940. Next is 65° in 2001.
Bluffton’s center stands about 1,360 ft above sea level. Within three miles the land runs from 1,300 ft to 1,410 ft, a difference of 110 ft: gently rolling country. The highest named summit within 15 miles is Mount Nebo, about 1,540 ft, 10 miles southeast.
Under the town center the state geologic map shows Foliated to gneissic tonalite, granodiorite, and diorite (tonalite, granodiorite, diorite), from the Neoarchean, 2.5 to 2.8 billion years old.
The section below crosses 5 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.
Tonalite, granodiorite, diorite. Age: Neoarchean, 2.5 to 2.8 billion years old. About 10 mi of the line.
Metabasalt, greenstone. Age: Neoarchean, 2.5 to 2.8 billion years old. About 6 mi of the line.
Dioritic, granodiorite. Age: Archean to Paleoproterozoic. About 5 mi of the line.
Granitic. Age: Neoarchean, 2.5 to 2.8 billion years old. About 4 mi of the line.
Granodiorite, diorite. Age: Neoarchean, 2.5 to 2.8 billion years old. About 0.5 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 Bluffton reaches the Gulf of America by way of the Leaf, the Redeye, the Crow Wing and the Mississippi: about 2,040 river miles.
Lake on the way: Lake Pepin.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Bluffton; river miles along the main stem, rounded.
Bluffton has a warm-summer humid continental climate. Summer afternoons average 79° in July; winter nights fall to about −2° in January. About 28 inches of rain fall in a normal year.
On November 14 Bluffton normally reaches 37° and falls to 22°. The record high is 63°, in 1981; the record low 6°, in 1965. The most rain on this date, 0.47 in, fell in 2024.
Normals 1991–2020 and records since 1940 at Ottertail, 15 miles west-southwest. NOAA, through RCC-ACIS.
