The Oshawa 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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76° on Nov. 14, 1999, the hottest reading for this week of the year since 1893. Next is 73° in 2012.
Oshawa’s center stands about 980 ft above sea level. Within three miles the land runs from 960 ft to 1,010 ft, a difference of 50 ft: nearly flat ground.
Under the town center the state geologic map shows Upper Cambrian (sandstone, siltstone, shale), from the Cambrian, 487 to 497 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 59×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Sandstone, siltstone, shale. Age: Cambrian, 487 to 497 million years old. About 16 mi of the line.
Dolostone, sandstone. Age: Early Ordovician, 471 to 487 million years old. About 5 mi of the line.
Sandstone, siltstone, shale. Age: Middle Cambrian to Cambrian, 487 to 521 million years old. About 3 mi of the line.
Claystone, siltstone, sandstone. Age: Early Cretaceous, 100 to 113 million years old. About 0.4 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 Oshawa reaches the Gulf of America by way of Sevenmile Creek, the Minnesota and the Mississippi: about 1,930 river miles.
Lake on the way: Lake Pepin.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Oshawa; river miles along the main stem, rounded.
Oshawa has a warm-summer humid continental climate. Summer afternoons average 82° in July; winter nights fall to about 3° in January. A normal year brings about 38 inches of snow; with the rain, that comes to about 32 inches of water.
On November 14 Oshawa normally reaches 43° and falls to 23°. The record high is 76°, in 1999; the record low −8°, in 1959. The most rain on this date, 1.50 in, fell in 1997.
Normals 1991–2020 and records since 1893 at St. Peter, 7 miles east-northeast, 180 ft lower. NOAA, through RCC-ACIS.
