The Ontario 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.
Showers likely
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Mostly sunny; warmer
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78° on Nov. 11, 2020, the hottest reading for this week of the year since 1922. Next is 77° in 1928.
Ontario’s center stands about 450 ft above sea level. Within three miles the land runs from 340 ft to 540 ft, a difference of 200 ft: rolling country. The highest named summit within 15 miles is Baker Hill, about 930 ft, 15 miles south-southwest.
Under the town center the state geologic map shows Irondequoit Limestone thru Kodak Sandstone (shale), from the Silurian, 428 to 445 million years old.
The section below crosses 6 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 42×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Dolostone. Age: Silurian, 425 to 428 million years old. About 5 mi of the line.
Shale. Age: Silurian, 422 to 428 million years old. About 5 mi of the line.
Shale. Age: Late Ordovician to Silurian, 434 to 459 million years old. About 3 mi of the line.
Shale. Age: Silurian, 428 to 445 million years old. About 2 mi of the line.
Shale. Age: Silurian, 422 to 428 million years old. About 1 mi of the line.
Shale. Age: Silurian, 428 to 434 million years old. About 0.9 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 Ontario reaches Lake Ontario by way of Dennison Creek: about 3 river miles. From the lake it goes down the St. Lawrence to the Atlantic.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Ontario; river miles along the main stem, rounded.
Ontario has a warm-summer humid continental climate. Summer afternoons average 79° in July; winter nights fall to about 16° in January. A normal year brings about 105 inches of snow; with the rain, that comes to about 40 inches of water.
On November 14 Ontario normally reaches 48° and falls to 32°. The record high is 70°, in 1994; the record low 12°, in 1996. The most rain on this date, 0.85 in, fell in 1972.
Normals 1991–2020 and records since 1922 at Sodus 1 W, 10 miles east. NOAA, through RCC-ACIS.
