The Portsmouth 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 cloudy
Mostly cloudy
Mostly sunny
Partly cloudy
Mostly sunny
Mostly sunny
Mostly sunny
82° on Nov. 11, 2020, the hottest reading for this week of the year since 1893. Next is 80° in 1902.
Portsmouth’s center stands about 940 ft above sea level. Within three miles the land runs from 490 ft to 1,020 ft, a difference of 530 ft: hilly country. The highest named summit within 15 miles is Campbell Hill, about 1,120 ft, 9 miles north-northwest.
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 28×. 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, siltstone, sandstone. Age: Devonian to Carboniferous, 324 to 422 million years old. About 15 mi of the line.
Shale, siltstone. Age: Carboniferous, 299 to 324 million years old. About 6 mi of the line.
Shale, sandstone. Age: Devonian to Carboniferous, 324 to 422 million years old. About 2 mi of the line.
Shale, black-shale. Age: Devonian, 359 to 422 million years old. About 0.6 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 Portsmouth reaches the Gulf of America by way of Munn Run, the Ohio and the Mississippi: about 1,590 river miles.
970 miles of the trip are on the Mississippi.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Portsmouth; river miles along the main stem, rounded.
Portsmouth has a hot-summer humid continental climate. Summer afternoons average 87° in July; winter nights fall to about 23° in January. About 43 inches of rain fall in a normal year.
On November 14 Portsmouth normally reaches 57° and falls to 34°. The record high is 79°, in 1955; the record low 10°, in 1986. The most rain on this date, 1.36 in, fell in 2024.
Normals 1991–2020 and records since 1893 at Portsmouth-Sciotoville, 3 miles east, 400 ft lower. NOAA, through RCC-ACIS.
