The St. Martin 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.
Mostly sunny
Mostly sunny; warmer
Partly cloudy
Partly cloudy
Mostly cloudy
Partly cloudy
Showers likely
69° on Nov. 13, 1999, the hottest reading for this week of the year since 1954. Next is 66° in 2025.
St. Martin’s center stands about 1,170 ft above sea level. Within three miles the land runs from 1,110 ft to 1,280 ft, a difference of 170 ft: gently rolling country.
Under the town center the state geologic map shows Granite, from the Paleoproterozoic, 1.6 to 1.8 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 63×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Age: Paleoproterozoic, 1.6 to 1.8 billion years old. About 6 mi of the line.
Orthogneiss, schist. Age: Paleoproterozoic, 1.6 to 2.5 billion years old. About 6 mi of the line.
Schist, slate. Age: Paleoproterozoic, 1.6 to 2.5 billion years old. About 5 mi of the line.
Volcanic, sedimentary, hypabyssal. Age: Paleoproterozoic, 1.6 to 2.5 billion years old. About 5 mi of the line.
Conglomerate, sandstone, mudstone. Age: Late Cretaceous, 72 to 100 million 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 St. Martin reaches the Gulf of America by way of the Sauk and the Mississippi: about 1,960 river miles.
Lakes on the way: Lake Pepin and Zumwalles Lake.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of St. Martin; river miles along the main stem, rounded.
St. Martin has a warm-summer humid continental climate. Summer afternoons average 81° in July; winter nights fall to about 0° in January. A normal year brings about 39 inches of snow; with the rain, that comes to about 29 inches of water.
On November 14 St. Martin normally reaches 39° and falls to 22°. The record high is 64°, in 2016; the record low −5°, in 2018. The most rain on this date, 0.34 in, fell in 2024.
Normals 1991–2020 and records since 1954 at Melrose, 10 miles north-northwest. NOAA, through RCC-ACIS.
