The Port Gibson 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.
Chance of showers
Mostly cloudy
Mostly cloudy
Mostly sunny; warmer
Mostly sunny
Partly cloudy
Partly cloudy
74° on Nov. 11, 2020, the hottest reading for this week of the year since 1969. Next is 71° in 1989.
Port Gibson’s center stands about 520 ft above sea level. Within three miles the land runs from 420 ft to 650 ft, a difference of 230 ft: rolling country. The highest named summit within 15 miles is Lincoln Hill, about 930 ft, 13 miles south-southwest.
Under the town center the state geologic map shows Camillus and Syracuse Formations (shale), from the Silurian, 422 to 428 million years old.
The section below crosses 9 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 39×. 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: Silurian, 422 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.
Dolostone. Age: Silurian, 425 to 428 million years old. About 5 mi of the line.
Shale, limestone. Age: Middle Devonian, 384 to 388 million years old. About 4 mi of the line.
Dolostone. Age: Silurian, 422 to 428 million years old. About 3 mi of the line.
Shale. Age: Middle Devonian, 384 to 394 million years old. About 1 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale. 3 smaller units along the line are not listed.
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 Port Gibson reaches Lake Ontario by way of the Erie Canal, the Clyde, the Seneca and the Oswego: about 100 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 Port Gibson; river miles along the main stem, rounded.
Port Gibson has a warm-summer humid continental climate. Summer afternoons average 80° in July; winter nights fall to about 16° in January. A normal year brings about 57 inches of snow; with the rain, that comes to about 35 inches of water.
On November 14 Port Gibson normally reaches 47° and falls to 32°. The record high is 65°, in 2005; the record low 14°, in 2019. The most rain on this date, 0.62 in, fell in 1972.
Normals 1991–2020 and records since 1969 at Geneva Research Farm, 13 miles south-southeast, 200 ft higher. NOAA, through RCC-ACIS.
