The Jefferson 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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75° on Nov. 11, 2022, the hottest reading for this week of the year since 1953. Next is 73° in 1989.
Jefferson’s center stands about 890 ft above sea level. Within three miles the land runs from 800 ft to 930 ft, a difference of 130 ft: gently rolling country. The highest named summit within 15 miles is Bald Hill, about 1,180 ft, 13 miles east-northeast.
Under the town center the state geologic map shows Ellsworth Shale, from the Late Devonian, 359 to 384 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 55×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Shale. Age: Late Devonian, 359 to 384 million years old. About 16 mi of the line.
Shale. Age: Carboniferous, 324 to 359 million years old. About 8 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 Jefferson reaches Lake Michigan by way of Cobus Creek and the Saint Joseph: about 80 river miles. From there it moves on through the Great Lakes, over Niagara Falls and down the St. Lawrence to the Atlantic.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Jefferson; river miles along the main stem, rounded.
Jefferson has a warm-summer humid continental climate. Summer afternoons average 82° in July; winter nights fall to about 16° in January. About 42 inches of rain fall in a normal year.
On November 14 Jefferson normally reaches 48° and falls to 31°. The record high is 73°, in 1989; the record low 10°, in 2019. The most rain on this date, 1.32 in, fell in 1957.
Normals 1991–2020 and records since 1953 at Dowagiac 1 W, 10 miles north-northwest, 150 ft lower. NOAA, through RCC-ACIS.
