The Sylvan 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
Partly cloudy
Partly cloudy
Chance of showers
Partly cloudy
Showers likely
69° on Nov. 17, 1953, the hottest reading for this week of the year since 1911. Next is 64° in 1913.
Sylvan’s center stands about 1,210 ft above sea level. Within three miles the land runs from 1,170 ft to 1,410 ft, a difference of 240 ft: rolling country. The highest named summit within 15 miles is Ghost Hill, about 1,600 ft, 13 miles north-northwest.
Under the town center the state geologic map shows Mille Lacs and North Range Groups and equivalent sedimentary rocks (siltstone, graywacke, slate), from the Paleoproterozoic, 1.6 to 2.5 billion years old.
The section below crosses 3 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 50×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Siltstone, graywacke, slate. Age: Paleoproterozoic, 1.6 to 2.5 billion years old. About 14 mi of the line.
Quartzite, conglomerate, mudstone. Age: Paleoproterozoic, 1.6 to 2.5 billion years old. About 7 mi of the line.
Granitic. Age: Neoarchean, 2.5 to 2.8 billion years old. About 4 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 Sylvan reaches the Gulf of America by way of the Crow Wing and the Mississippi: about 1,970 river miles.
Lake on the way: Lake Pepin.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Sylvan; river miles along the main stem, rounded.
Sylvan has a warm-summer humid continental climate. Summer afternoons average 79° in July; winter nights fall to about −1° in January. About 27 inches of rain fall in a normal year.
On November 14 Sylvan normally reaches 38° and falls to 23°. The record high is 65°, in 1953; the record low −5°, in 1911. The most rain on this date, 0.54 in, fell in 1926.
Normals 1991–2020 and records since 1911 at Gull Lake Dam, 6 miles north-northeast. NOAA, through RCC-ACIS.
